Apparatus and method for manufacturing micro solder pattern forming substrate

Abstract

[Problem] The present application provides a manufacturing device and a manufacturing method capable of efficiently manufacturing a fine solder pattern formed substrate, which is a substrate capable of realizing high-density mounting and high reliability by filling a fine solder in a fine pattern such as a through-hole, a non-through-hole, a groove, and the like. [Solution] The above problem is solved in the following manner: A manufacturing device of a fine solder pattern formed substrate, which is a fine solder pattern formed substrate (10) in which a fine pattern (2) formed on a substrate (1) is filled with a metal solder layer (3c), the manufacturing device comprising: an organic fatty acid-containing solution treatment device (12) that brings an organic fatty acid-containing solution (21) into contact with a substrate in which an electrically conductive layer (3b) composed of copper or a copper alloy is formed on an inner surface of the fine pattern (2); and a metal solder layer forming device (13) that supplies a stream (5a) of a nickel-containing molten solder (5) treated with the organic fatty acid-containing solution to the substrate (1) that has been brought into contact with the organic fatty acid-containing solution (21), thereby filling the fine pattern (2) with a metal solder layer (3c).

Description

Technical Field

[0001] This invention relates to an apparatus and method for manufacturing a substrate with micro-solder patterns. Solder is filled into micro-patterns such as through-holes, non-through-holes, and trenches to achieve high-density mounting and high reliability. More specifically, this invention relates to a technique that immerses micro-patterns in an organic fatty acid solution, followed by liquid-liquid displacement between the immersed organic fatty acid solution and nickel-containing molten solder, thereby achieving gapless high-density mounting and high reliability. Background Technology

[0002] With the miniaturization, thinning, lightweighting, high-speed, high-functionality, and multi-functionality of electronic devices, the miniaturization and thinning of substrates for high-density mounting of electronic components such as semiconductor devices, as well as the narrow-pitch and multi-pin nature of external electrode terminals, are also under development. Examples of these substrates include those called BGA (Ball Grid Array) and CSP (Chip Size Package), with various structures proposed by semiconductor manufacturers and substrate manufacturers. On the other hand, printed circuit boards (PCBs) mounting semiconductor devices and other electronic components require miniaturization of circuit wiring and multi-layering to accommodate complex circuit traces or accommodate the narrow-pitch and multi-pin nature of semiconductor devices.

[0003] As multilayer substrates, known types include through-hole multilayer substrates (Through-Hole Multilayer Substrates) connecting interlayer circuits via through-holes, IVH (Interstitial Via Holes) multilayer substrates connecting interlayers via IVHs, and multilayer substrates fabricated using build-up processes. In recent years, glass and quartz substrates have become particularly favored as substrates. Glass and quartz substrates offer high flexibility in thickness and size, are readily available, relatively inexpensive, and possess excellent smoothness and flatness, which is beneficial for the formation of narrow-pitch micro-wiring. They also have low linear thermal expansion coefficients, excellent mounting and dimensional stability, excellent chemical stability, high insulation, and excellent transmission characteristics. Furthermore, the development of electrical discharge machining (EDM) and laser processing techniques for creating micro-through-holes in glass and quartz substrates is also advantageous. Therefore, there is a demand for using glass and quartz substrates as substrates to extend through-holes and achieve smaller diameters and narrower pitches.

[0004] A technique for filling through-holes with metal has also been proposed. This through-hole filling technique typically involves forming the through-hole using electrical discharge machining (EDM), laser processing, etc. A thin metal layer is first formed within the through-hole using known methods such as sputtering, vapor deposition, CVD, or electroless plating to achieve conductivity. Then, the entire thin metal layer is electroplated by passing an electric current through it, thereby filling the through-hole with metal. In this conventional method, to completely fill a micro-hole of, for example, 50 μm with electroplating, a plating thickness of approximately 25 μm is required on the inner wall surface. However, for such micro-holes, the aspect ratio of the substrate thickness (through-hole length) to the hole diameter (through-hole diameter) is large, making it difficult to fill the inner wall surface with an electroplated layer. Furthermore, voids or seams may be generated within the through-hole conductor.

[0005] Various technologies have been proposed to address this problem. For example, although not all through-holes are filled with metal, Patent Document 1 proposes a glass circuit board capable of forming microcircuits. This technology involves laminating a first insulating resin with good filling properties into both sides of the glass core substrate, where metal circuits are formed in the through-holes, to effectively suppress voids generated within the through-holes and achieve long-term connection reliability. Furthermore, by increasing the amount of inorganic filler in the first insulating resin, the curing shrinkage of the insulating resin filling the through-holes is suppressed, thereby suppressing depressions caused by curing shrinkage directly above the through-holes and ensuring the flatness of the resin surface.

[0006] Furthermore, although not entirely filled with metal, Patent Document 2 also proposes a circuit board with multiple through-holes, wherein the inner walls of the through-holes are coated with a copper plating layer, and the interior of the through-holes is filled with resin. This technology improves quality by eliminating deviations in the thickness of the copper plating layer based on the density of the through-holes, and includes forming a plating film of approximately fixed thickness along the inner walls of the through-holes and filling the interior of the through-holes with a conductive filler.

[0007] Existing technical documents

[0008] Patent documents

[0009] Patent Document 1: Japanese Patent Application Publication No. 2020-182006

[0010] Patent Document 2: Japanese Patent Application Publication No. 2023-131615

[0011] Patent Document 3: Japanese Patent No. 5191616

[0012] Patent Document 4: Japanese Patent No. 5079169

[0013] Patent Document 5: Japanese Patent No. 5079170

[0014] Patent Document 6: Japanese Patent No. 6150881

[0015] Patent Document 7: Japanese Patent No. 5129898 Summary of the Invention

[0016] The problem the invention aims to solve

[0017] As exemplified by the aforementioned examples, while research is underway to achieve smaller diameters and narrower pitches for long through-holes using high-performance glass or quartz substrates, the electroplating process creates a conductive layer on the inner surface of the through-hole. This may result in plating solution or chemical components remaining within the through-hole, or defects or voids in the through-hole conductor, potentially hindering high reliability. Particularly in through-holes with high aspect ratios, insufficient plating penetration to various corners and the formation of voids have become significant challenges.

[0018] Similar to the case of filling through-holes with metal, micro-sized non-through-holes or trenches (also known as slits) that are difficult to fill with metal even when desired to reach every corner also present the same problems and may compromise high reliability. In particular, when attempting to fill smaller non-through-holes (referring to non-through holes) with diameters of, for example, around 5 to 50 μm, existing methods, compared to the case of through-holes, may result in residual plating solution or chemical components inside the non-through-hole, or defects or voids in the filled conductor.

[0019] Furthermore, Patent Document 3 discloses a method for forming solder bumps on a mounting substrate having fine copper electrodes. This method involves overlapping a mask with openings for forming solder bumps on a substrate having a copper electrode pattern, and forming solder bumps by spraying jets of molten solder through the openings of the mask. However, this method requires cumbersome processes such as preparing mask components and overlapping them, and also presents cost challenges.

[0020] Furthermore, the applicant has proposed welding apparatuses and methods as shown in Patent Documents 4 to 6. Patent Document 4 provides a welding apparatus and method capable of performing highly reliable welding with low cost and high yield. Specifically, the welding apparatus includes at least: a first organic fatty acid solution bath in which a component to be processed, having a copper electrode, is immersed; a space portion containing a vapor atmosphere of an organic fatty acid solution that is the same as or substantially the same as the organic fatty acid solution, and the space portion having, in the horizontal direction, a jetting means for spraying a jet of molten solder toward the copper electrode provided on the component to be processed, and a jetting means for spraying liquid to remove any remaining molten solder; and a second organic fatty acid solution bath in which the component to be processed, after the remaining molten solder has been removed, is again immersed in the organic fatty acid solution. This welding apparatus enables highly reliable welding with low cost and high yield.

[0021] Patent Document 5 provides a welding apparatus and welding method capable of performing highly reliable welding with low cost and high yield. Specifically, it comprises: a first processing unit for immersing a component having a copper electrode in a solution containing organic fatty acids and moving the immersed component horizontally in the solution; a second processing unit equipped with a spraying means that sprays a jet of molten solder toward the component while pulling the processed component upward into a space of vapor atmosphere; a third processing unit equipped with a spraying means that, after moving the processed component horizontally in the space, lowers it into the solution containing organic fatty acids while spraying the remaining molten solder on the component to remove it; and a fourth processing unit that, after moving the processed component horizontally in the solution containing organic fatty acids, pulls it upward and removes it from the solution.

[0022] Patent Document 6 is an improvement on the aforementioned Patent Documents 4 and 5, providing a space-saving novel welding apparatus and method capable of high-reliability welding with low cost and high yield. Specifically, the welding apparatus includes: a first processing unit housing a component having an electrode to be welded; a second processing unit, which is hermetically separated from the first processing unit by a first opening / closing means, and which delivers the component fed into the first processing unit to a next third processing unit; a third processing unit, which is hermetically separated from the second processing unit by a second opening / closing means, and which contacts the component fed into the second processing unit with an organic fatty acid solution and moves the component horizontally; and a fourth processing unit, which includes a molten solder adhesion means for attaching the component that has been horizontally moved in the third processing unit. The component is moved to the upper space to allow molten solder to adhere to the aforementioned electrode; and a molten solder removal means removes any remaining molten solder from the adhered molten solder in the aforementioned space; a fifth processing unit moves the component that has moved downward in the aforementioned fourth processing unit horizontally; a sixth processing unit is hermetically separated from the aforementioned fifth processing unit by a third opening and closing means provided between it and the aforementioned fifth processing unit, and sends the component fed into the aforementioned fifth processing unit to the next seventh processing unit; and a seventh processing unit is hermetically separated from the aforementioned sixth processing unit by a fourth opening and closing means provided between it and the aforementioned sixth processing unit, and removes the component fed into the aforementioned sixth processing unit.

[0023] In the welding apparatuses described in Patent Documents 4 to 6, there are instances where filling the metal in fine patterns such as through holes, non-through holes, and trenches is insufficient. Furthermore, in the simple immersion method of the welding apparatuses described in Patent Documents 4 to 6, air adhering to and trapped in the corners or minute edges of the fine pattern cannot be expelled by surface tension, potentially resulting in unfilled areas where the solder is not fully applied, or wire breakage due to solder corrosion (copper erosion). Moreover, the substrates commonly used at the time of the inventions in Patent Documents 4 to 6 sometimes cannot adequately form fine through holes, non-through holes, and trenches, making them insufficient for applications involving finely processed quartz or glass substrates with excellent dimensional stability.

[0024] The present invention was made to solve the above-mentioned problems, and its purpose is to provide a manufacturing apparatus and manufacturing method that can efficiently manufacture a micro solder pattern forming substrate, wherein the micro solder pattern forming substrate is filled with solder in micro patterns such as micro through holes, non-through holes, and trenches to achieve high-density mounting and high reliability.

[0025] Solution for solving the problem

[0026] (1) The micro-solder pattern forming substrate manufacturing apparatus (hereinafter referred to as the "manufacturing apparatus") of the present invention is an apparatus for manufacturing a micro-solder pattern forming substrate in which a micro-pattern formed thereon is filled with a metal solder layer. The manufacturing apparatus includes: an organic fatty acid solution processing apparatus that contacts the aforementioned substrate with an organic fatty acid solution, wherein a conductive layer made of copper or a copper alloy is formed on the inner surface of the aforementioned micro-pattern; and a metal solder layer forming apparatus that supplies a stream of nickel-containing molten solder treated with an organic fatty acid solution to the substrate that has been in contact with the aforementioned organic fatty acid solution, so as to fill the aforementioned micro-pattern with a metal solder layer. Here, "inner surface" refers to the surface constituting the micro-pattern, and in this application, it is used in the sense of including the inner wall surface.

[0027] In patent documents 3 and 7, the inventors proposed a method for manufacturing a substrate or electronic component that significantly suppresses copper corrosion, such as in existing dipping processes, and prevents copper corrosion during subsequent mounting processes. This invention further develops these fundamental technologies by immersing a fine pattern in an organic fatty acid solution, followed by a liquid-liquid displacement reaction between the immersed organic fatty acid solution and a nickel-containing molten solder, thereby seamlessly filling the corners of the fine pattern with a metal solder layer. These techniques enable gapless, high-density mounting and high reliability.

[0028] (2) The manufacturing apparatus as described in (1) above, wherein the aforementioned organic fatty acid solution processing apparatus is equipped with a depressurization processing means, by which the air attached to the aforementioned fine pattern is degassed and the aforementioned organic fatty acid solution is immersed into each corner of the aforementioned fine pattern.

[0029] According to the present invention, the air adhering to the micro-pattern is degassed by a depressurization process, and an organic fatty acid solution is immersed into each corner of the micro-pattern. Therefore, the nickel-containing molten solder can be immersed into each corner of the micro-pattern through liquid-liquid displacement between the immersed organic fatty acid solution and the nickel-containing molten solder. As a result, a metal solder layer can be formed in each corner of the micro-pattern without defects or voids.

[0030] (3) The manufacturing apparatus as described in (1) above, wherein the aforementioned organic fatty acid solution processing apparatus has a first container and a second container respectively having organic fatty acid solutions of different viscosities, the first container having an organic fatty acid solution of lower viscosity than the second container, and the second container having an organic fatty acid solution of the same concentration as the organic fatty acid solution used in the aforementioned metal solder layer forming apparatus for refining the molten solder.

[0031] According to the present invention, the organic fatty acid solution containing a low viscosity is easily immersed into the micro-pattern using a first container. Then, using a second container, an organic fatty acid solution of the same concentration as the refined molten solder solution can be easily immersed into the micro-pattern already immersed in the low-viscosity organic fatty acid solution. As a result, molten solder can be easily immersed into the micro-pattern, and the metal solder layer can fill every corner of the micro-pattern without defects or gaps.

[0032] (4) The manufacturing apparatus as described in (3) above, wherein the first container is provided with a depressurization process, by which the air attached to the micro-pattern is degassed and the low-viscosity organic fatty acid solution is immersed into each corner of the micro-pattern.

[0033] According to the present invention, since the first container containing the low-viscosity organic fatty acid solution is equipped with a depressurization process, air adhering to the micro-pattern can be degassed, and the low-viscosity organic fatty acid solution can be immersed into every corner of the micro-pattern. As a result, since the subsequent immersion of the organic fatty acid solution in the second container becomes easier, the nickel-containing molten solder can be immersed into every corner of the micro-pattern through liquid-liquid displacement between the organic fatty acid solution and the nickel-containing molten solder. As a result, a metal solder layer can be formed in every corner of the micro-pattern without defects or voids.

[0034] (5) The manufacturing apparatus as described in (1) or (2) above, wherein a supply device is provided to supply the substrate on which a conductive layer of copper or copper alloy is formed on the inner surface of the aforementioned micro-pattern to the aforementioned organic fatty acid solution processing apparatus.

[0035] According to the present invention, a substrate with a conductive layer made of copper or a copper alloy formed on the inner surface of a fine pattern can be prepared in advance, and the prepared substrate can be supplied to an apparatus containing an organic fatty acid solution. As a result, efficient manufacturing can be performed by separating wet processing, such as organic fatty acid solution processing, from processing methods such as PVD (Physical Vapor Deposition) or photolithography.

[0036] (6) The manufacturing apparatus as described in (1) or (2) above, wherein a conductive layer forming apparatus is provided, which forms a conductive layer made of copper or a copper alloy on the inner surface of the aforementioned fine pattern.

[0037] According to the present invention, a conductive layer forming apparatus may also be provided on the inner surface of a fine pattern formed on a substrate to form a conductive layer made of copper or a copper alloy, as an apparatus in a process prior to the treatment of an organic fatty acid solution. This conductive layer forming apparatus may be provided adjacent to an organic fatty acid solution treatment apparatus, or it may be provided in a different location within the same factory or in different factories.

[0038] (7) The manufacturing apparatus as described in (1) or (2) above, wherein the aforementioned fine pattern is selected from a single type of pattern or a composite pattern of two or more types of patterns, including through holes, non-through holes, grooves and slits.

[0039] According to the present invention, for a single type of pattern or a composite pattern of two or more selected from through holes, non-through holes, trenches and slits, a metal solder layer can be formed in all corners without defects or gaps.

[0040] (8) The manufacturing apparatus as described in (1) or (2) above, wherein the concentration A (mass%) of the organic fatty acid solution in contact with the aforementioned fine pattern and the concentration B (mass%) of the organic fatty acid solution in processing the aforementioned nickel-containing molten solder are A=B or A <B。

[0041] According to the present invention, by setting the concentration A of the organic fatty acid solution in contact with the micro-pattern as above, the liquid-liquid displacement between the organic fatty acid solution immersed in the micro-pattern and the nickel-containing molten solder becomes easier.

[0042] (9) The manufacturing apparatus as described in (1) or (2) above, wherein the substrate is a quartz substrate or a glass substrate, and has a substrate support plate for holding and conveying the substrate.

[0043] According to the present invention, since a substrate support plate is provided for holding and conveying a quartz substrate or a glass substrate, a quartz substrate or glass substrate with excellent dimensional stability and capable of forming fine patterns can be safely conveyed. Furthermore, the substrate support plate preferably has a structure that fixes one or two of the aforementioned substrates in a manner that exposes the substrate surface, allowing a stream of nickel-containing molten solder to be directly sprayed toward the substrate surface of the fixed substrate via a spray nozzle or the like.

[0044] (10) The manufacturing method of the micro-solder pattern forming substrate of the present invention (hereinafter referred to as the "manufacturing method") is a method for manufacturing a micro-solder pattern forming substrate formed by filling a micro-pattern formed on a substrate with a metal solder layer. The manufacturing method of the micro-solder pattern forming substrate includes: an organic fatty acid solution treatment step, in which an organic fatty acid solution is brought into contact with the aforementioned substrate, wherein a conductive layer made of copper or a copper alloy is formed on the inner surface of the aforementioned micro-pattern; and a metal solder layer forming step, in which a liquid flow of nickel-containing molten solder treated with an organic fatty acid solution is supplied to the substrate that is in contact with the aforementioned organic fatty acid solution to fill the aforementioned micro-pattern with a metal solder layer.

[0045] (11) The manufacturing method as described in (10) above, wherein in the aforementioned organic fatty acid solution treatment step, a depressurization treatment is performed to remove air from the aforementioned fine pattern and to allow the aforementioned organic fatty acid solution to immerse into the aforementioned fine pattern.

[0046] (12) The manufacturing method as described in (10) above, wherein the aforementioned organic fatty acid solution treatment step has a first container and a second container respectively having organic fatty acid solutions with different viscosities, the first container having an organic fatty acid solution with a lower viscosity than the second container, and the second container having an organic fatty acid solution with the same concentration as the organic fatty acid solution used in the aforementioned metal solder layer formation step.

[0047] (13) As described in (12) above, the first container is subjected to depressurization to remove air from the micro-pattern, and the low-viscosity organic fatty acid solution is immersed into the micro-pattern.

[0048] (14) The micro-solder pattern forming substrate of the present invention is a substrate manufactured using the micro-solder pattern forming substrate manufacturing apparatus or manufacturing method of the present invention described above. The metal layer formed on the micro-pattern of the substrate is composed of at least, sequentially, a conductive layer made of copper or a copper alloy, a mixed layer of a copper corrosion prevention layer and a copper-tin intermetallic compound layer, and a metal solder layer formed by solidification of nickel-containing molten solder from the inner wall surface of the micro-pattern toward the stacking direction. In addition, a base conductive layer formed on the substrate surface may also be provided below the aforementioned conductive layer.

[0049] According to the present invention, since the metal layer formed in the fine pattern is formed with the above-described configuration, the metal solder layer, in particular, formed by solidification of nickel-containing molten solder, does not suffer from the presence of plating solution or chemical components remaining in the metal layer formed in the fine pattern, as is the case with conventional electroplating. Furthermore, the metal layer is free from defects or voids. Moreover, since the nickel-containing molten solder is refined using an organic fatty acid solution, oxygen components, metal oxides, impurities, etc., present in the molten solder are refined and removed. As a result, no defects or voids are formed in the metal solder layer. In addition, since the copper corrosion prevention layer has a layer of intermetallic compounds that prevent copper corrosion, copper corrosion of the copper plating or copper alloy plating constituting the conductive layer can be suppressed, and excessive formation of copper-tin intermetallic compounds with poor mechanical strength can be suppressed. In addition, nickel-containing molten solder treated with organic fatty acid solution has a lower oxygen content and can be observed to have a fine granular crystal structure compared to untreated molten solder, while the columnar structure of untreated molten solder is not observed. This point confirms the difference.

[0050] The manufacturing apparatus and manufacturing method of the present invention described above may also have the following configurations (specific details of the invention):

[0051] (A) The aforementioned organic fatty acid solution treatment apparatus includes a pretreatment means, which immerses a cleaning solution or surface treatment solution into the aforementioned micro-pattern before immersing the aforementioned organic fatty acid solution into the aforementioned micro-pattern.

[0052] (B) The aforementioned organic fatty acid solution contains palmitic acid with 16 carbon atoms.

[0053] (C) The aforementioned metal solder layer forming apparatus includes a molten solder removal device that removes the remaining molten solder after supplying the aforementioned nickel-containing molten solder liquid stream (supplied by the molten solder supply device).

[0054] (D) The aforementioned molten solder is mainly composed of tin and contains at least nickel as a secondary component.

[0055] (E) The viscosity of the aforementioned molten solder is in the range of 0.002 Pa·s to 0.004 Pa·s.

[0056] (F) The formation of the metal solder layer by the aforementioned metal solder layer forming apparatus is carried out in a vapor atmosphere containing an organic fatty acid solution.

[0057] (G) The aforementioned metal solder layer forming apparatus sprays the aforementioned molten solder toward the aforementioned micro-pattern or at a predetermined angle.

[0058] (H) In the case where the aforementioned conductive layer and the inner surface of the aforementioned fine pattern are formed together on the substrate surface, a conductive layer removal device is provided before the aforementioned metal solder layer forming device to remove the conductive layer formed on the aforementioned substrate surface.

[0059] (I) The aforementioned conductive layer forming apparatus includes: a first conductive layer forming apparatus for forming a first conductive layer on the aforementioned inner surface; and a second conductive layer forming apparatus for forming a second conductive layer on the first conductive layer, which is composed of a copper plating layer or a copper alloy plating layer.

[0060] (J) The aforementioned first conductive layer forming apparatus is formed by a PVD apparatus or CVD apparatus for forming conductive materials or composite materials selected from ITO, Cr, Ti, Al, Au, Ag, Cu, Ni and Mo.

[0061] (K) The aforementioned conductive layer forming apparatus forms a chemically plated copper layer or a chemically plated copper alloy layer after a chemical plating catalyst is provided on the aforementioned inner surface.

[0062] The effects of the invention

[0063] According to the present invention, a manufacturing apparatus and method are provided that can efficiently manufacture a micro-solder pattern forming substrate. This micro-solder pattern forming substrate achieves high-density mounting and high reliability by filling solder into micro-patterns such as micro-through holes, non-through holes, and trenches. In particular, the present invention employs a technique (manufacturing apparatus, manufacturing method) that involves immersing the micro-patterns in an organic fatty acid solution, followed by a liquid-liquid displacement reaction between the immersed organic fatty acid solution and nickel-containing molten solder, thereby filling the micro-patterns with a seamless metal solder layer. These techniques enable gapless high-density mounting and high reliability. Attached Figure Description

[0064] Figure 1 This is a cross-sectional photograph showing an example of a micro-solder pattern forming substrate (with a through-hole diameter of 40 μm) manufactured by the micro-solder pattern forming substrate manufacturing apparatus of the present invention.

[0065] Figure 2 This is a cross-sectional photograph showing another example (through-hole diameter of 20 μm) of a micro-solder pattern forming substrate manufactured by the micro-solder pattern forming substrate manufacturing apparatus of the present invention.

[0066] Figure 3 This is a planar photograph (A) and an enlarged photograph (B) showing an example of a micro solder pattern forming substrate manufactured by the micro solder pattern forming substrate manufacturing apparatus of the present invention.

[0067] Figure 4This is an electron microscope photograph showing an example of a micro-patterning substrate prepared for manufacturing a micro-solder pattern forming substrate.

[0068] Figure 5 It is an electron microscope image showing the morphology after the first conductive layer is formed in the through-hole.

[0069] Figure 6 This is a photograph showing the microstructure of a metal solder layer formed from molten solder treated with a solution containing organic fatty acids.

[0070] Figure 7 This is a photograph showing the microstructure of a metal solder layer formed from molten solder that has not been treated with a solution containing organic fatty acids.

[0071] Figure 8 This is an explanatory diagram illustrating one example of a manufacturing process performed by the micro solder pattern forming substrate manufacturing apparatus of the present invention.

[0072] Figure 9 This is an explanatory diagram illustrating another example of the manufacturing process performed by the micro solder pattern forming substrate manufacturing apparatus of the present invention.

[0073] Figure 10 This is an explanatory diagram illustrating another example of the manufacturing process performed by the micro solder pattern forming substrate manufacturing apparatus of the present invention.

[0074] Figure 11 (A) is a schematic cross-sectional view of an intermetallic compound layer formed between a copper plating layer and a metal solder layer in a micro-solder pattern forming substrate manufactured by the present invention, and (B) is a schematic cross-sectional view of an intermetallic compound layer formed with conventional molten solder.

[0075] Figure 12 This is a graph showing the temperature dependence of viscosity for molten solder (a) treated with an organic fatty acid solution and molten solder (b) not treated with an organic fatty acid solution.

[0076] Figure 13 This is a schematic diagram illustrating a device for spraying molten solder to form a metal solder layer.

[0077] Figure 14 This is a schematic diagram illustrating an apparatus for spraying a solution containing organic fatty acids to remove excess molten solder.

[0078] Figure 15 This is a schematic illustration of an example of an apparatus for spraying molten solder to form a metal solder layer and an apparatus for spraying an organic fatty acid solution to remove excess molten solder.

[0079] Figure 16This is a schematic illustration of another example of an apparatus for spraying molten solder to form a metal solder layer and an apparatus for spraying an organic fatty acid solution to remove excess molten solder.

[0080] Figure 17 This is an explanatory diagram illustrating an example of a decompression processing step and apparatus used in the manufacturing technology (manufacturing apparatus, manufacturing method, hereinafter the same) for forming a substrate with the micro solder pattern of the present invention.

[0081] Figure 18 is an explanatory diagram illustrating an example of a molten solder adhesion process and apparatus for the application of the manufacturing technology of forming a substrate with fine solder patterns according to the present invention.

[0082] Figure 19 This is an explanatory diagram illustrating an example of a residual solder removal process and apparatus in the application of the manufacturing technology of forming a substrate with a fine solder pattern according to the present invention.

[0083] Figure 20 This is an explanatory diagram illustrating an example of a liquid removal process and apparatus used in the manufacturing technology of forming a substrate with fine solder patterns according to the present invention.

[0084] Figure 21 This is a schematic diagram illustrating an example of a processing procedure and apparatus in a single-tank container for the application of the manufacturing technology of forming a substrate with fine solder patterns according to the present invention. (A) shows the immersion process, and (B) shows the decompression process.

[0085] Figure 22 is a schematic diagram showing an example of a processing procedure and apparatus in a double-tank container for the application of the manufacturing technology of forming a substrate with fine solder patterns according to the present invention. (A) is an example of a processing procedure and apparatus using a pretreatment liquid or a low-concentration organic fatty acid solution, and (B) is an example of a depressurization processing procedure and apparatus using a solution containing organic fatty acids of normal concentration.

[0086] Figure 23 This is an explanatory diagram showing an example of one of the apparatuses constituting the micro solder pattern forming substrate manufacturing apparatus of the present invention.

[0087] Figure 24 shows an example of two substrates mounted on a substrate support plate.

[0088] Figure 25 This is one example of mounting multiple substrates on a substrate support plate used for multiple substrates.

[0089] Figure 26 This is a schematic perspective view showing an example of a substrate for forming a fine solder pattern using the manufacturing technique of the present invention. (A) is an example of a substrate with trenches, and (B) is an example of a substrate with non-through holes.

[0090] Figure 27This is a schematic perspective view showing another example of a substrate for forming a fine solder pattern using the manufacturing technique of the present invention. (A) is an example of a substrate that combines trenches and non-through holes, and (B) is an example of a substrate that combines trenches, non-through holes, and through holes.

[0091] Figure 28 shows that... Figure 27 (B) is a schematic diagram of an example of a substrate formed by forming a fine solder pattern of trenches, non-through holes and through holes filled with a metal solder layer.

[0092] Figure 29 This is a photograph illustrating one example of a micro-solder pattern forming substrate (a substrate with solder patterns formed in micro-grooves) manufactured using the micro-solder pattern forming substrate manufacturing technology of the present invention.

[0093] Figure 30 This is a schematic top view of an example of a substrate manufacturing apparatus for forming fine solder patterns according to the present invention.

[0094] Figure 31 yes Figure 30 A schematic front view of the manufacturing apparatus shown. Detailed Implementation

[0095] Regarding the micro-solder pattern forming substrate manufacturing apparatus and manufacturing method of the present invention, please refer to the accompanying drawings. Figure 1 The following description illustrates preferred embodiments of the invention, but is not limited to these embodiments, and also includes various applications or variations. Furthermore, in this application, "the present invention" may be referred to as "the embodiments of this application".

[0096] The manufacturing technology for a micro-solder pattern forming substrate of the present invention refers to a manufacturing apparatus and a manufacturing method for a micro-solder pattern forming substrate (hereinafter sometimes referred to as "manufacturing apparatus" and "manufacturing method," respectively). Each device constituting the manufacturing apparatus, such as an organic fatty acid solution treatment apparatus, a metal solder layer forming apparatus, a supply apparatus, a conductive layer forming apparatus, a conductive layer removal apparatus, a pretreatment means, and a molten solder removal apparatus, can be replaced by an organic fatty acid solution treatment step, a metal solder layer forming step, a supply step, a conductive layer forming step, a conductive layer removal step, a pretreatment step, and a molten solder removal step, respectively, as constituent elements of the manufacturing method.

[0097] Additionally, "anti-corrosion layer" refers to a layer that prevents copper or copper alloys from being dissolved by solder (e.g., by the diffusion of copper atoms). "Inner surface" of the micropattern refers to the surface constituting the micropattern; in this application, it is used to include the meaning of "inner wall surface." "Substrate surface" refers to the top and / or bottom surface of the substrate. "Upper," "lower," "above," and "below" refer to "upper" and "lower" in a top view. "Immersing the micropattern in a solution" ("immersion" is sometimes also used with the terms "impregnation" or "contact") means spreading the solution throughout all corners of the micropattern. "Liquid-liquid displacement" means that the liquid immersed in all corners of the micropattern is replaced or exchanged for another liquid.

[0098] [Manufacturing apparatus and manufacturing method]

[0099] The manufacturing apparatus 20 of the present invention is an apparatus for manufacturing a micro-solder pattern forming substrate 10, in which a micro-pattern 2 formed on the substrate 1 is filled with a metal solder layer 3c. The manufacturing apparatus includes: an organic fatty acid solution processing apparatus 12, which contacts an organic fatty acid solution 21 to the substrate 1, the substrate 1 having a conductive layer 3b made of copper or a copper alloy formed on the inner surface of the micro-pattern 2; and a metal solder layer forming apparatus 13, which supplies a flow 5a of nickel-containing molten solder 5 treated with the organic fatty acid solution to the substrate 1 that has been in contact with the aforementioned organic fatty acid solution 21, so as to fill the aforementioned micro-pattern 2 with the metal solder layer 3c.

[0100] The manufacturing method of the present invention is a method for manufacturing a micro-solder pattern forming substrate 10, in which a micro-pattern 2 formed on the substrate 1 is filled with a metal solder layer 3c. The manufacturing method includes: an organic fatty acid solution treatment step, which contacts the substrate 1 with an organic fatty acid solution 21, wherein a conductive layer 3b made of copper or a copper alloy is formed on the inner surface of the micro-pattern 2; and a metal solder layer forming step, which supplies a flow 5a of nickel-containing molten solder 5 treated with the organic fatty acid solution to the substrate 1 that has been in contact with the aforementioned organic fatty acid solution 21, so as to fill the aforementioned micro-pattern 2 with the metal solder layer 3c.

[0101] This invention relates to the following technology (manufacturing apparatus, manufacturing method): a micro-pattern 2 is immersed in an organic fatty acid solution 21 by treatment with an organic fatty acid solution, and then the immersed organic fatty acid solution 21 is subjected to liquid-liquid displacement with a nickel-containing molten solder 5, thereby filling the metal solder layer 3c seamlessly in every corner of the micro-pattern 2. This technology achieves gapless, high-density mounting and high reliability.

[0102] In this invention, a substrate 1 having a conductive layer 3b made of copper or a copper alloy formed on the inner surface of a micropattern 2 is prepared in advance. The substrate 1 is then processed by an organic fatty acid solution processing apparatus 12 to bring it into contact with an organic fatty acid solution 21. Therefore, before supplying molten solder 5 to the conductive layer 3b to form a metal solder layer 3c, the organic fatty acid solution 21 can contact (immerse) each corner of the micropattern 2. As a result, oxide films generated on the surface of the conductive layer 3b formed on the micropattern 2 can be removed and / or cleaned, while the organic fatty acid solution 21 can be immersed into each corner of the micropattern 2. Then, a metal solder layer forming apparatus 13, which supplies a flow 5a of nickel-containing molten solder 5 treated with the organic fatty acid solution to the micropattern 2 that has been immersed in the organic fatty acid solution 21, performs a liquid-liquid exchange between the organic fatty acid solution 21 and the nickel-containing molten solder 5, thereby filling each corner of the micropattern 2 with the nickel-containing molten solder 5 to form the metal solder layer 3c. As a result, metal solder layers 3c can be easily and seamlessly filled into micro-patterns 2 such as through-holes, non-through-holes, trenches, and slits. Because these metal solder layers 3c form a copper erosion prevention layer (intermetallic compound layer) 4 on the surface of the conductive layer 3b to inhibit solder erosion, they achieve high-density mounting and high reliability without gaps while suppressing solder erosion in the micro-wiring pattern. The micro-solder pattern forming substrate 10 manufactured using this technology provides a highly reliable conductive micro-pattern substrate.

[0103] Furthermore, on the conductive layer 3b, a metal solder layer 3c formed by solidifying molten solder is formed using the metal solder layer forming apparatus 13, and this metal solder layer 3c is used to fill the fine patterns 2. Unlike existing methods, no plating solution or chemical components remain within these fine patterns filled with metal solder layer 3c, and no defects or voids are generated in the filled metal solder layer 3c. As a result, a micro-solder pattern forming substrate 10 that achieves high-density mounting and high reliability can be manufactured. In addition, since the molten solder 5 is refined using a solution containing organic fatty acids, oxygen components, metal oxides, impurities, etc., present in the molten solder 5 have been refined and removed. The metal solder layer 3c formed by the solidification of these molten solder 5 has the advantage of being free of defects or voids. Furthermore, since the molten solder 5 contains nickel, this nickel, together with copper and tin, forms an intermetallic compound that prevents the corrosion of copper. As a result, by suppressing the copper dissolution of the copper plating or copper alloy plating constituting the conductive layer 3b, the excessive formation of copper-tin intermetallic compounds with poor mechanical strength within the copper plating or copper alloy plating can be suppressed. Furthermore, the molten solder 5 treated with an organic fatty acid solution has a lower oxygen content and exhibits a fine granular crystalline structure compared to the molten solder not treated with an organic fatty acid solution (see reference). Figure 6 ), and the columnar structure of untreated molten solder was not observed (see reference). Figure 7The difference can be confirmed at this point.

[0104] Furthermore, when the metal solder layer 3c is formed using the metal solder layer forming apparatus 13 with molten solder 5 treated with an organic fatty acid solution, since each corner of the micro-pattern 2 is immersed (synonymous with impregnation or contact) in the organic fatty acid solution 21, the molten solder 5 treated with the organic fatty acid solution can easily penetrate into the micro-pattern 2. As a result, liquid-liquid displacement between the organic fatty acid solution 21 and the molten solder 5 treated with the organic fatty acid solution can be easily achieved within the micro-pattern 2.

[0105] The constituent elements will be described in detail below. First, the micro-solder pattern forming substrate 10 manufactured by the manufacturing apparatus and manufacturing method of the present invention will be described, and the manufacturing apparatus and manufacturing method will also be described.

[0106] <Substrate>

[0107] Substrate 1 is not particularly limited and can be any substrate with fine patterns 2 (through holes, non-through holes, trenches, slits, etc.). Examples of substrate 1 include paper phenolic substrates (FR-1, FR-2, etc.), paper epoxy resin substrates (FR-3, etc.), glass composite substrates (CEM-3, etc.), glass epoxy resin substrates, glass polyimide substrates, high-frequency substrates (PTFE and other fluororesin substrates, etc.), metal substrates (aluminum substrates, etc.), PPO substrates (polyphenylene ether), BT resin substrates (bismaleimide triazine), ceramic substrates (alumina substrates, etc.), low-temperature co-fired ceramic substrates (LTCC substrates), glass substrates (FR-4, etc.), glass core substrates, quartz substrates, etc.

[0108] While not specifically limited, quartz substrates or glass substrates are preferred substrates 1. Glass substrates or quartz substrates offer advantages such as high flexibility in thickness and size, easy availability, relatively low cost, excellent smoothness and flatness, favorable conditions for forming narrow-pitch micro-wires, low coefficient of linear thermal expansion, excellent mounting and dimensional stability, excellent chemical stability, high insulation, and excellent transmission characteristics. Furthermore, the micro-patterns 2 can be electrically or laser-processed. By using quartz substrates or glass substrates, a micro-solder pattern forming substrate 10 that achieves high-density mounting and high reliability can be provided. Particularly in the case of manufacturing the micro-solder pattern forming substrate 10, the substrate 1 is sometimes sprayed with molten solder 5 heated to approximately 250°C, or exposed to processing temperatures of 150°C to 300°C. However, even at these temperatures, the micro-solder pattern forming substrate 10 that achieves high-density mounting and high reliability can still be manufactured by using quartz substrates or glass substrates, which have low coefficients of linear thermal expansion and excellent dimensional and chemical stability.

[0109] Glass or quartz substrates are easily processed by electrical discharge machining (EDM) or laser processing. For example, in the case of through-holes, they offer advantages in lengthening the through-holes and achieving narrower diameters and spacing. While EDM or laser processing is not detailed in this application, known methods can be used. Furthermore, through-holes of any thickness can be drilled with a predetermined diameter and distance, or non-through-holes or trenches of a predetermined depth and width, thus forming other types of fine patterns. Although examples of fine patterns such as through-holes, non-through-holes, and trenches are listed above, the method is not limited to these.

[0110] The thickness, size, area, and shape of substrate 1 are not particularly limited. For example, the thickness can be about 0.1 mm to 1 mm, and the shape of the substrate can be, for example, a quadrilateral, a circle, an ellipse, etc.

[0111] <Micro Patterns>

[0112] Micro-pattern 2 can include micro-patterns such as through holes, non-through holes, and grooves, without particular limitation. For example, regarding through holes... Figure 4 As shown, the holes provided in the substrate 1, whose inner surfaces are coated, are generally referred to as through holes. In this invention, the entire through-hole 2c of the through hole is covered with a metal layer 3 (see reference 1). Figures 1 to 3 Metallizing is performed by filling with 8 to 10) of the material. In this application, this is sometimes referred to as a through-hole for convenience. This fine pattern 2 can be formed, as described above, by electrical discharge machining or laser processing. In addition to through-holes, other types of patterns can also be formed, such as... Figures 26 to 27 The example shown is filled with a metal solder layer 3c in the fine trenches 2a, non-through holes 2b, and through holes 2c. Furthermore, while through holes are used as a representative example in the following descriptions for ease of understanding, the same applies to fine patterns such as non-through holes or trenches.

[0113] Micro-pattern 2 if Figures 1 to 3 As illustrated in the example, its interior is filled with a conductive material. Specifically, a metal layer 3 is formed on the inner surface of the micropattern 2 using a method that leaves no residue of plating solution or plating solution components. The composition of the metal layer 3 is described later. Figure 8 and Figure 9 As described in the description section, an example may be composed of a first conductive layer 3a disposed on the inner surface of the micro-pattern 2, a second conductive layer 3b disposed on the first conductive layer 3a and composed of a copper plating layer or a copper alloy plating layer, and a metal solder layer 3c disposed on the second conductive layer 3b and filling the micro-pattern 2. Furthermore, as... Figure 10As shown, an example can be formed by a conductive layer 3b, consisting of a copper plating or copper alloy plating, disposed on the inner surface of the micro-pattern 2, and a metal solder layer 3c disposed on the conductive layer 3b and filling the micro-pattern 2. Furthermore, this metal layer 3 is suitable for... Figure 26 and Figure 27 The fine patterns shown (grooves 2a, non-through holes 2b, through holes 2c) are also formed as shown in Figure 28.

[0114] The through-length of the micropattern 2 is not particularly limited, and can be categorized as ranging from 0.1 mm to 1 mm, depending on the substrate thickness. Furthermore, the diameter of the micropattern 2 is also not particularly limited, and can range from 5 μm to 500 μm. In particular, by setting the length of the micropattern 2 to 0.1 mm to 0.5 mm and the diameter to 10 μm to 50 μm, a substrate for forming micro-solder patterns that achieves both small diameter and narrow pitch for elongated vias can be provided. Additionally, these dimensional factors... Figure 26 and Figure 27 The same measurement range is also shown in the fine patterns (groove 2a, non-through hole 2b, through hole 2c).

[0115] Regarding the fine pattern 2, it can also be expressed by the aspect ratio (L / D) obtained by dividing the depth (L) of the fine pattern 2 by the diameter (D) of the fine pattern 2. For example, L / D can be 4 or more, L / D can be 10 or more, or L / D can be 20 or more.

[0116] While there are no particular limitations on the spacing between the micropatterns 2, it is designed with consideration for its relationship to the aperture. This invention allows for narrow spacing, for example, from 50 μm to 200 μm. Furthermore, these spacings... Figure 26 and Figure 27 The same measurement range is also shown in the fine patterns (groove 2a, non-through hole 2b, through hole 2c).

[0117] <Metallic Layer>

[0118] In the fine pattern 2, if... Figures 1 to 3 For example, it is filled with metal layer 3. Metal layer 3 can be filled with metal layer 3 as follows: Figures 8 to 10 The illustrated process and the apparatus for performing the process are used to form the structure. The invention is characterized in that the final filled metal layer is a metal solder layer 3c, and this metal solder layer 3c is filled with nickel-containing molten solder 5 treated with an organic fatty acid solution 21.

[0119] (Metal solder layer)

[0120] First, let's explain the metal solder layer 3c. The metal solder layer 3c is placed on the already formed conductive layer 3b, which is composed of a copper plating or a copper alloy plating. Figures 8 to 10 On the surface, to fill the fine pattern 2. Additionally, the conductive layer 3b is... Figure 8 and Figure 9 It is disposed on the first conductive layer 3a, forming a two-layer structure together with the first conductive layer 3a. Furthermore, in Figure 10 In the middle, the conductive layer 3b is composed of a copper plating or a copper alloy plating.

[0121] On the conductive layer 3b side of the metal solder layer 3c or on the second conductive layer 3b side, such as Figure 11 As shown, an intermetallic compound layer 4 is formed, which combines with the copper components constituting the conductive layer 3b or the second conductive layer 3b to prevent copper corrosion. Since the metal solder layer 3c is filled with nickel-containing molten solder 5 treated with an organic fatty acid solution 21, the nickel, copper, and tin together form the intermetallic compound layer 4 (also called a copper corrosion prevention layer) to prevent copper corrosion. As a result, the formation of this intermetallic compound layer 4 suppresses copper corrosion of the copper plating constituting the conductive layer 3b or the second conductive layer 3b, and also suppresses the excessive formation of copper-tin intermetallic compounds (CuSn intermetallic compound layer 7) with poor mechanical strength.

[0122] The metal solder layer 3c is primarily composed of tin and contains at least nickel as a secondary component. More preferably, it contains one or more secondary components selected from silver, copper, zinc, bismuth, antimony, and germanium. Because the metal solder layer 3c is formed with this composition, a highly reliable micro-solder pattern forming substrate 10 can be provided.

[0123] (Molten solder)

[0124] As for the specific molten solder 5 used to form the metal solder layer 3c, a molten lead-free solder with tin as the main component and at least nickel as a secondary component is preferred. Furthermore, a low-melting-point molten solder containing at least nickel as a secondary component in a tin-bismuth based solder is also preferred. In such a molten lead-free solder, one or more components selected from copper, germanium, and phosphorus may be arbitrarily included as secondary components. Additionally, silver may be included to further improve wettability. For example, SnNi-based solders, SnCuNi-based solders, SnGeNi-based solders, SnPNi-based solders, SnCuGeNi-based solders, SnCuGePNi-based solders, SnAgCuNi-based solders, SnZnAlNi-based solders, SnAgCuGeNi-based solders, SnSbNi-based solders, etc., can be used. Furthermore, examples of low-melting-point solders include SnBiNi-based solders, SnBiZnNi-based solders, and SnBiAgInNi-based solders. Figure 13 As shown, molten solder 5 is sprayed from the spray nozzle 31 (filling means) toward the fine pattern 2 as a heated molten liquid stream 5a. The heating temperature is arbitrarily selected according to the solder composition, and is usually set in the range of 150°C to 300°C as a suitable temperature.

[0125] As a preferred molten solder 5, examples include pentagonal solder alloys of Sn-Ni-Ag-Cu-Ge, quaternary solder alloys of Sn-Ni-Cu-Ge, ternary solder alloys of Sn-Ni-Cu, and ternary solder alloys of Sn-Ni-Ge. The pentagonal solder of Sn-Ni-Ag-Cu-Ge is preferably, for example, a solder alloy containing, for example, nickel: 0.01% to 0.5% by mass, silver: 2% to 4% by mass, copper: 0.1% to 1% by mass, germanium: 0.001% to 0.02% by mass, with the balance being tin. The quaternary solder of Sn-Ni-Cu-Ge is preferably, for example, a solder alloy containing, for example, nickel: 0.01% to 0.5% by mass, copper: 0.1% to 1% by mass, germanium: 0.001% to 0.02% by mass, with the balance being tin. The preferred Sn-Ni-Cu ternary solder is, for example, a solder alloy comprising, for example, nickel: 0.01% to 0.5% by mass, copper: 0.1% to 1% by mass, and the balance: tin. The molten solder 5 composed of these solder alloys forms a CuNiSn intermetallic compound layer 4, which serves as a copper corrosion prevention layer 4 and can stably suppress the corrosion of copper in the copper plating or copper alloy plating constituting the conductive layer 3b. A particularly preferred composition for forming the CuNiSn intermetallic compound layer 4 is a solder alloy containing nickel: 0.01% to 0.1% by mass. When soldering using these solder alloys, it is preferable to use the molten solder 5 at a temperature of 240°C to 260°C.

[0126] Furthermore, the low-melting-point solder containing bismuth can further reduce the heating temperature of the molten solder 5. By adjusting its composition, for example, the soldering temperature can be reduced to around 150°C. The composition of the bismuth-containing solder is also the same as described above, preferably containing 0.01% to 0.5% by mass of nickel, more preferably 0.01% to 0.1% by mass of nickel. Thus, a low-temperature molten solder 5 can be obtained that can easily form a CuNiSn intermetallic compound layer 4 as a copper corrosion prevention layer.

[0127] In addition, other elements such as zinc, copper, germanium, and antimony may be added as needed, but in any case, the solder composition is preferably to contain at least 0.01% to 0.5% by mass of nickel, more preferably 0.01% to 0.1% by mass of nickel.

[0128] (Contains organic fatty acid solution)

[0129] The molten solder 5 is treated with an organic fatty acid solution. The molten solder 5 treated with the organic fatty acid solution is effective in easily forming a copper corrosion prevention layer 4 on the surface of the conductive layer 3b, which has been cleaned with the organic fatty acid solution. The organic fatty acid solution 21 is preferably a solution containing organic fatty acids with 12 to 20 carbon atoms. While organic fatty acids with 11 or fewer carbon atoms can also be used, these organic fatty acids are hygroscopic and, while not unusable, are not ideal. Furthermore, organic fatty acids with 21 or more carbon atoms have drawbacks such as high melting points, poor penetration, and difficulty in processing. Palmitic acid with 16 carbon atoms is preferred as a representative example. Palmitic acid with only 16 carbon atoms is particularly preferred as an organic fatty acid, but organic fatty acids with 12 to 20 carbon atoms, such as stearic acid with 18 carbon atoms, can also be included as needed.

[0130] The organic fatty acid solution 21 is preferably composed of 5% to 25% organic fatty acids by mass, with the remainder being ester-synthetic oil. By using this organic fatty acid solution 21, oxides or impurities (including plating solution residues, hereinafter the same) present on the surface of the conductive layer 3b formed on the inner surface of the fine pattern 2 can be selectively absorbed, and the surface of the conductive layer 3b can be cleaned. The organic fatty acid solution 21 is particularly preferably composed of about 10% (e.g., 5% to 15% by mass) palmitic acid with 16 carbon atoms. Furthermore, the organic fatty acid solution 21 does not contain metal salts such as nickel or cobalt salts, or additives such as antioxidants. If the concentration of organic fatty acids is less than 5% by mass, the efficiency of selectively absorbing oxides or impurities present on the surface of the conductive layer 3b for purification is slightly lower, and management at low concentrations can sometimes become cumbersome. On the other hand, if the concentration of organic fatty acids exceeds 25% by mass, the viscosity of the organic fatty acid solution 21 will increase, leading to problems such as fuming and foul odor in high-temperature environments exceeding 280°C. Therefore, the content of organic fatty acids is preferably 5% to 20% by mass, and especially when only palmitic acid with 16 carbon atoms is used, it is preferably about 10% by mass (e.g., 5% to 15% by mass).

[0131] By contacting the liquid containing the organic fatty acid solution 21, oxides or impurities present on the surface of the conductive layer 3b can be removed for cleaning. Furthermore, a coating (not shown) of the organic fatty acid constituting the organic fatty acid solution 21 is formed on the surface of the conductive layer 3b in contact with the organic fatty acid solution 21. This coating has the advantage of cleaning the surface of the conductive layer 3b and thus inhibiting oxidation of the conductive layer 3b surface, thereby minimizing the formation of copper oxide film or the adhesion of impurities. As a result, the molten solder 5 can contact the surface of the conductive layer 3b in a state where these oxides or impurities are as absent as possible from the electrode surface. Therefore, a copper corrosion prevention layer 4 with a uniform thickness and free of defects can be formed on the clean conductive layer 3b surface.

[0132] The temperature of the liquid containing the organic fatty acid solution 21 is not particularly limited, but a relatively high temperature is preferred. For example, a temperature range of 50°C to 280°C is preferred. If the temperature exceeds 280°C, fumes or foul odors may sometimes be produced.

[0133] (Copper corrosion prevention layer)

[0134] Copper corrosion prevention layer 4 Figure 11 As shown in (A), when molten solder 5 is supplied to conductive layer 3b and the fine pattern 2 is filled with metal solder layer 3c, a layer is formed between conductive layer 3b and metal solder layer 3c. This copper corrosion prevention layer 4 is a compound layer formed by the combination of nickel and tin components contained in the molten solder 5 with the copper component constituting conductive layer 3b. Defects are minimized, and it is formed with a uniform thickness. By forming this intermetallic compound layer 4, corrosion of copper in conductive layer 3b constituting copper plating or copper alloy plating can be suppressed or stopped. As a result, excessive formation of copper-tin intermetallic compounds (CuSn intermetallic compound layer 7) with poor mechanical strength can be suppressed. On the other hand, as a nickel-free molten solder material, for example, when using a ternary lead-free solder composed of Ag: 3% by mass, Cu: 0.5% by mass, and the balance: Sn, ... Figure 11 As shown in (B), there is no CuNiSn intermetallic compound layer that acts as a copper corrosion prevention layer 4, and instead a thick CuSn intermetallic compound layer 7 with poor mechanical strength is formed.

[0135] The thickness of the copper corrosion prevention layer 4 is not particularly limited, but it is likely to fall within the range of approximately 0.5 μm to 3 μm. If the thickness of the copper corrosion prevention layer 4 is too thick, the copper corrosion prevention layer itself may develop cracks or fissures, so the thickness of the thickest part is preferably less than 3 μm. It is particularly preferred that the thinnest part of the copper corrosion prevention layer 4 is more than 0.5 μm and the thickest part is less than 3 μm, and the overall average thickness of the copper corrosion prevention layer 4 is 1 μm to 2 μm. In addition, the thickness can be calculated from the results of cross-section observation using a scanning electron microscope or a transmission electron microscope, based on the results of 100 measurement points.

[0136] The copper corrosion prevention layer 4 is composed primarily of tin and contains at least nickel as a secondary component. If the molten solder 5 contains one or more of silver, copper, zinc, bismuth, antimony, and germanium, these are included as optional secondary components. In this case, the CuNiSn intermetallic compound layer forming the copper corrosion prevention layer 4 is generated by cooling the molten solder 5 to a temperature below approximately 217°C. This allows for a minimum thickness of 0.5 μm or more for the generated CuNiSn intermetallic compound layer, with an average thickness ranging from 1 μm to 2 μm. This ensures that a crack-free and non-fragile CuNiSn intermetallic compound layer is uniformly generated between the conductive layer 3b and the solder layer 3c, preventing damage or disappearance of the conductive layer 3b due to the corrosion of copper contained in the conductive layer 3b.

[0137] (Molten solder treated with a solution containing organic fatty acids)

[0138] The molten solder 5 is treated with an organic fatty acid solution 21. Specifically, a solution containing 5% to 25% by mass of organic fatty acids with 12 to 20 carbon atoms is heated to 180°C to 280°C, and the heated solution is brought into contact with and stirred to mix the molten solder 5. This cleans the molten solder 5 from contamination by oxides and impurities (including flux components, etc. The same applies hereinafter), resulting in molten solder 5 with oxides or impurities removed. Then, for example, the mixture containing the molten solder 5 with oxides or impurities removed is introduced into a reservoir containing an organic fatty acid solution, and the cleaned molten solder 5, separated by gravity difference in the reservoir containing the organic fatty acid solution, is pumped back from the bottom of the reservoir to a reservoir for lead-free solder solution. This purification process suppresses the increase in copper and impurity concentrations in the molten solder 5 used as a liquid stream over time, and prevents oxides or impurities from being carried into the reservoir for lead-free solder solution. As a result, since the compositional changes of the molten solder 5 in the lead-free solder reservoir over time can be suppressed, a stable molten solder 5 with high bonding reliability can be used.

[0139] Since the treated molten solder 5 is as free of oxides and impurities as possible, the deviation in the characteristic quality of the metal solder layer 3c formed from the molten solder 5 is minimized, and it contributes to the quality stability over time. Compared with molten solder that has not been refined with an organic fatty acid solution, the treated molten solder 5 has achieved the preferred result of excellent solder wettability. In addition, compared with untreated molten solder, the molten solder 5 treated with an organic fatty acid solution has a lower oxygen content, and the following can be observed: Figure 6 The microgranular crystalline structure shown in (A) and (B) is not observed, and the columnar structure of untreated molten solder is not visible. Figure 7(A) (B)), the difference can be confirmed at this point.

[0140] Furthermore, the molten solder 5 treated with an organic fatty acid solution exhibited a significantly lower viscosity compared to the molten solder without such treatment. The viscosity of the molten solder 5 treated with the organic fatty acid solution was in the range of 0.002 Pa·s to 0.004 Pa·s in the molten state. Specifically, in Figure 12 In the example, a pentagonal lead-free solder consisting of Ni: 0.05% by mass, Ge: 0.005% by mass, Ag: 3% by mass, Cu: 0.5% by mass, with the balance being Sn is used. The viscosity of the molten solder 5, treated with an organic fatty acid solution, is as follows: Figure 12 The symbol 'a' represents a viscosity of 0.003 Pa·s to 0.004 Pa·s. In contrast, even for the same pentagonal lead-free solder, the viscosity of unrefined molten solder in the molten state ranges from 0.005 Pa·s to 0.008 Pa·s. Specifically, the viscosity of unrefined molten solder is as follows: Figure 12 As indicated by symbol 'b', even for the same pentagonal lead-free solder, the viscosity ranges from 0.005 Pa·s to 0.006 Pa·s, a difference of approximately 1.5 times. Furthermore, the molten solders used in the examples and comparative examples described later have a melting point of approximately 217°C, and the aforementioned viscosity range was obtained over a temperature range of at least 240°C to 260°C. Viscosities were measured using a vibrating plate viscometer.

[0141] The treated molten solder 5 has different properties (viscosity and solder wettability) compared to the unrefined molten solder, such as... Figure 13 As shown, this means that when the liquid stream 5a of molten solder 5 is sprayed onto the substrate 1, it can easily penetrate into every corner of the micro-pattern 2 containing the organic fatty acid solution by displacing it with the solution 21, and spread evenly with good solder wettability. In particular, before spraying the liquid stream 5a of molten solder 5 onto the substrate 1, the solution 21 containing the organic fatty acid solution is pre-immersed into the micro-pattern 2 ( Figure 13 The conductive layer 3b within the fine pattern 2 is cleaned by removing copper oxides or impurities from its surface using an organic fatty acid solution 21. The cleaned surface of the conductive layer 3b is then sprayed from a nozzle 31 with a stream 5a of molten solder 5, also refined with an organic fatty acid solution and having a viscosity within the aforementioned range (0.002 Pa·s to 0.004 Pa·s). This allows the molten solder 5 to wet and spread uniformly on the conductive layer 3b with good solder wettability. As a result, the nickel and tin components in the molten solder 5 combine with the copper components constituting the conductive layer 3b, causing a CuNiSn intermetallic compound layer, serving as a copper corrosion prevention layer 4, to form at every corner of the conductive layer 3b's surface and to fill the fine pattern 2 without gaps.

[0142] On the other hand, when an unrefined molten solder stream is sprayed onto the surface of the conductive layer 3b within the micro-pattern 2, the viscosity in the molten state is as high as 0.005 Pa·s or more and 0.008 Pa·s or less, so it does not wet and spread with good wettability as described above. Sometimes, the molten solder cannot be uniformly wetted and spread on the surface of the conductive layer 3b.

[0143] The temperature of the organic fatty acid solution used for refining is determined by the melting point of the molten solder 5 to be refined. The organic fatty acid solution and the molten solder 5 are stirred and contacted at a high temperature range at least above the melting point of the molten solder 5 (for example, solder with a melting point around 217°C is at 240°C to 260°C). Furthermore, from the perspective of smoke generation or energy saving, the upper limit temperature of the organic fatty acid solution is around 280°C, and it is desirable to be in the range of temperature above the melting point of the refined molten solder 5 up to 260°C. For example, a solder alloy with a melting point of around 217°C (nickel: 0.01% to 0.1% by mass), silver: 0.1% to 4% by mass), copper: 0.1% to 1% by mass), germanium: 0.001% to 0.01% by mass, and the balance tin) is used as molten solder 5 at a temperature of 240°C to 260°C. Therefore, the temperature of the organic fatty acid solution is also preferably around 240°C to 260°C.

[0144] <Conductive layer other than the metal solder layer>

[0145] Apart from the aforementioned metal solder layer 3c constituting metal layer 3, any conductive layer formed on the inner surface of the fine pattern 2 may be used. For example, a conductive layer could be... Figure 8 and Figure 9 As shown, a first conductive layer 3a is disposed on the inner surface of the fine pattern 2, and a second conductive layer 3b is disposed on the first conductive layer 3a and is composed of a copper plating layer or a copper alloy plating layer. A metal solder layer 3c is provided on this two-layer conductive layer, which can fill the fine pattern 2. Furthermore, other types of conductive layers, such as... Figure 10 As shown, the conductive layer 3b, which is composed of a copper plating or a copper alloy plating, can also be directly disposed on the inner surface of the micro-pattern 2 without the first conductive layer 3a. Alternatively, the micro-pattern 2 can be filled by providing a metal solder layer 3c on such a conductive layer 3b.

[0146] (Conductive layer, second conductive layer)

[0147] The layer system represented by symbol 3b is a copper plating layer or copper alloy plating layer provided as a layer below the aforementioned metal solder layer 3c. Figure 8 and Figure 9 The second conductive layer 3b in the middle system, in Figure 10The middle layer is "conductive layer 3b". The copper plating or copper alloy plating is preferably a chemical plating layer that is easy to form with a uniform plating thickness.

[0148] The plating solution for forming the electroless copper plating layer is not particularly limited, but for example, an electroless copper plating solution using sodium hypophosphite as a reducing agent can be cited as an example. Similarly, the plating solution for forming the electroless copper alloy plating layer is not particularly limited, but for example, an electroless copper-nickel plating solution using sodium hypophosphite as a reducing agent can be cited as an example. The thickness of the formed electroless plating layer is not particularly limited, but for example, approximately 1 μm to 10 μm is acceptable, preferably 2 μm to 6 μm. This thickness can be measured with a thickness gauge or by measuring the cross-section under a microscope.

[0149] In addition, chemical copper plating can utilize industrially common reducing chemical copper plating methods. Reducing chemical plating can be either non-catalytic or autocatalytic, without particular limitation. Examples of plating solutions include those containing copper salts (e.g., copper sulfate or copper chloride), reducing agents (e.g., formaldehyde, glyoxylic acid, hypophosphite, DMAB), complexing agents (e.g., Rochelle salt or EDTA), pH adjusters, and stabilizers.

[0150] (First conductive layer)

[0151] First conductive layer 3a, as shown Figure 5 As illustrated, the first conductive layer 3a is disposed on the inner surface of the fine pattern 2 and serves as the underlying layer when the second conductive layer 3b is formed. The first conductive layer 3a is selected from conductive materials or composites thereof, such as ITO, Cr, Ti, Al, Au, Ag, Cu, Ni, and Mo, and is preferably a PVD film or CVD film formed by PVD or CVD methods. By using the above-mentioned materials for the first conductive layer 3a, the second conductive layer 3b, which is composed of a chemical plating layer, can be easily formed on the first conductive layer 3a. The thickness of the first conductive layer 3a is not particularly limited and can be in the range of about 0.1 μm to 1.5 μm, or about 0.2 μm to 1 μm.

[0152] (other)

[0153] The substrate 10 is formed with a fine solder pattern filled with fine patterns 2, and wiring patterns can also be formed on one or both of the substrate surfaces 1a and 1b. Furthermore, although the metal solder layer 3c is flush with the substrate surface after the molten solder 5 protruding from the substrate surface is removed by a molten solder removal device / process, it can also be made to protrude from the substrate surfaces 1a and 1b by not removing the molten solder 5 or by removing it only slightly. By making the metal solder layer 3c protrude from the substrate surfaces 1a and 1b, this protruding portion can also be used as a land, pad, or solder bump around wiring or vias.

[0154] <Micro-solder pattern forming substrate>

[0155] The substrate 10, which is thus configured as a fine solder pattern forming substrate, is manufactured using the manufacturing apparatus / method for forming a fine solder pattern forming substrate described later. The substrate 1 has a metal layer 3 formed on the fine pattern 2, which, from the inner wall surface of the fine pattern 2 toward the stacking direction, is characterized by at least the following sequence: a conductive layer 3b made of copper or a copper alloy, a mixed layer comprising a copper etch-preventing layer 4 and a CuSn intermetallic compound layer 7, and a metal solder layer 3c formed by solidifying nickel-containing molten solder 5. Furthermore, a base conductive layer (e.g., a first conductive layer 3a) may be formed on the substrate surface below the conductive layer 3b.

[0156] Since the metal layer 3 formed on the micro-pattern 2 of the substrate 10 is formed with the above-described configuration, the metal solder layer 3c, which is solidified from nickel-containing molten solder 5, does not have residual plating solution or chemical components as seen in existing electroplating filling methods, and the metal layer is free from defects or voids. Furthermore, since the nickel-containing molten solder 5 is refined using an organic fatty acid solution, oxygen components, metal oxides, impurities, etc., present in the molten solder have been refined and removed. As a result, no defects or voids are formed in the metal solder layer 3c. In addition, since the copper corrosion prevention layer 4 has a layer of intermetallic compounds that prevent copper corrosion, it can suppress copper corrosion of the copper plating or copper alloy plating constituting the conductive layer 3b, and can suppress the excessive formation of copper-tin intermetallic compounds with poor mechanical strength. Furthermore, the nickel-containing molten solder 5 treated with an organic fatty acid solution has a lower oxygen content and exhibits a fine granular crystalline structure compared to the untreated molten solder, while the columnar structure characteristic of the untreated molten solder is not observed, thus confirming the difference. This fine solder patterning substrate 10 is expected to serve as a substrate for achieving high-density mounting and high reliability.

[0157] <Manufacturing apparatus / method>

[0158] The manufacturing apparatus for the micro-solder pattern forming substrate 10 of the present invention, such as... Figures 8 to 10 and Figures 17 to 25 As shown, a manufacturing apparatus for a micro-solder pattern forming substrate 10, in which a micro-pattern 2 formed on a substrate 1 is filled with a metal solder layer 3c, is provided. The manufacturing apparatus includes: an organic fatty acid solution processing apparatus 12, which contacts an organic fatty acid solution 21 with a conductive layer 3b made of copper or a copper alloy formed on the inner surface of the micro-pattern 2; and a metal solder layer forming apparatus 13, which supplies a flow 5a of nickel-containing molten solder 5 treated with the organic fatty acid solution to the substrate 1 in contact with the aforementioned organic fatty acid solution 21, so as to fill the aforementioned micro-pattern 2 with the metal solder layer 3c.

[0159] Furthermore, the manufacturing method of the micro-solder pattern forming substrate 10 of the present invention, such as... Figures 8 to 10 and Figures 17 to 25 As shown, a method for manufacturing a micro-solder pattern forming substrate 10, in which a micro-pattern 2 formed on a substrate 1 is filled with a metal solder layer 3c, comprises: an organic fatty acid solution treatment step, in which an organic fatty acid solution 21 is brought into contact with a substrate 1 on which a conductive layer 3b made of copper or a copper alloy is formed on the inner surface of the micro-pattern 2; and a metal solder layer forming step, in which a liquid flow 5a of nickel-containing molten solder 5 treated with an organic fatty acid solution is supplied to the substrate 1 in contact with the aforementioned organic fatty acid solution 21 to fill the aforementioned micro-pattern 2 with the metal solder layer 3c.

[0160] In addition, although there are instances below where it is expressed as "...apparatus / process", it is used to explain the meaning of both apparatus and method.

[0161] (Conductive layer forming apparatus / process)

[0162] The conductive layer forming apparatus / process is an apparatus / process for forming a conductive layer 3b made of copper or a copper alloy on the inner surface of the fine pattern 2. This conductive layer 3b, made of copper plating or a copper alloy plating, is disposed on the side of the inner metal solder layer 3c (i.e., the surface side). The manufacturing apparatus / manufacturing method of the present invention may or may not include this conductive layer forming apparatus / process. When the conductive layer forming apparatus / process is included, it can be provided as an apparatus / process preceding the organic fatty acid solution processing apparatus / process, or as an apparatus / process adjacent to the organic fatty acid solution processing apparatus / process. Furthermore, it can be provided in other locations within the same factory. It can also be provided in other factories (whether factories of the same company or different companies). Furthermore, a substrate 1 with a conductive layer 3b made of copper or a copper alloy formed can be obtained from the market and supplied to subsequent apparatus / processes.

[0163] This conductive layer forming apparatus / process can be <Example 1>, such as Figure 8 (A) to (C) or Figure 9 As shown in examples (A) to (D), a first conductive layer forming apparatus / process that includes forming a first conductive layer 3a on the inner surface of the fine pattern 2, and a second conductive layer forming apparatus / process that forms a second conductive layer 3b composed of a copper plating or a copper alloy plating on the first conductive layer 3a, can also be <Apparatus / Process Example 2>, such as... Figure 10As shown, an apparatus / process for forming a conductive layer 3b composed of a chemically plated copper layer or a chemically plated copper alloy layer is formed after a chemical plating catalyst 23 is provided on the inner surface of the fine pattern 2. In the conductive layer forming apparatus / process of apparatus / process example 2, it is not necessary to provide a first conductive layer that functions as a base layer for the conductive layer 3b composed of a copper layer or a copper alloy layer; the conductive layer 3b composed of a chemically plated copper layer or a chemically plated copper alloy layer can be formed without providing a first conductive layer that functions as a base layer for the conductive layer 3b composed of a copper layer or a copper alloy layer.

[0164] In addition, such as Figure 8 As shown in (B), when the conductive layers (3a, 3b) and the inner surfaces of the fine patterns 2 are formed together on the substrate surfaces 1a, 1b, it is preferable that... Figure 8 Before the metal solder layer forming apparatus / process in (E), there is a conductive layer removal apparatus / process for removing the conductive layers (3a, 3b) formed on the substrate surfaces 1a and 1b. The removal method is not particularly limited, but the conductive layers (3a, 3b) on the substrate surfaces 1a and 1b can be removed by mechanical grinding.

[0165] In addition, such as Figure 9 As shown in (A), the resist film 22 can also be provided only on substrate surfaces 1a and 1b, and then... Figure 9 As shown in (B), a first conductive layer 3a is formed on the substrate surfaces 1a and 1b and within the micropattern 2 using the above method, and then as follows... Figure 9 As shown in (C), a stripping resist film can also be applied to remove the first conductive layer 3a disposed on the substrate surfaces 1a and 1b, for example, by photolithography. Subsequently, as... Figure 9 As shown in (D), a chemical plating can be formed on the first conductive layer 3a, and the first conductive layer 3a and the second conductive layer 3b can be formed within the fine pattern 2. Subsequently, it can also be achieved by... Figure 8 or Figure 10 The same process is used to create a micro-solder pattern forming substrate 10.

[0166] (Supply equipment / process)

[0167] This supply device / process supplies a substrate 1, on which a conductive layer 3b made of copper or a copper alloy is formed on the inner surface of the micropattern 2, to the organic fatty acid solution processing device / process described later. This supply device / process only needs to supply the manufactured or obtained substrate 1 to the next organic fatty acid solution processing device / process, and does not necessarily need to be a separate device / process. For example, it can be included in the conductive layer forming device / process described above, or included in the organic fatty acid solution processing device / process described later.

[0168] This supply device / process prepares a substrate 1 in advance with a conductive layer 3b made of copper or a copper alloy formed on the inner surface of the fine pattern 2, and the prepared substrate 1 can be supplied to an organic fatty acid solution processing device / process. As a result, efficient manufacturing can be performed by separating wet processing such as organic fatty acid solution processing from processing such as PVD or photolithography.

[0169] (Including organic fatty acid solution treatment equipment / process)

[0170] The present invention is characterized in that: after the conductive layer forming apparatus / process and before the metal solder layer forming apparatus / process, such as Figure 8 (D) Figure 9 (E) Figure 10 (D) Figure 17 , Figure 21 As shown in Figure 22, an organic fatty acid solution processing apparatus 12 / process includes a substrate 1 having a conductive layer 3b made of copper or a copper alloy formed on the inner surface of a micropattern 2, in which an organic fatty acid solution 21 is brought into contact. Through this apparatus 12 / process, before forming the metal solder layer 3c, the micropattern 2 is immersed in the organic fatty acid solution 21, and in the subsequent metal solder layer forming apparatus 13 / process, the immersed organic fatty acid solution 21 undergoes liquid-liquid displacement with the nickel-containing molten solder 5, thereby allowing the metal solder layer 3c to be filled seamlessly into every corner of the micropattern. As a result, the metal solder layer 3c can be easily filled into elongated through-holes, narrow-diameter through-holes, or fine trenches or narrow-diameter non-through-holes, achieving gapless high-density mounting and high reliability.

[0171] (Contains an organic fatty acid solution impregnated within the fine pattern)

[0172] The organic fatty acid solution treatment apparatus 12 is preferably equipped with means for immersing (or impregnating) the organic fatty acid solution 21 into the micro-pattern. As such means, it is preferable to use any of the following: (1) a pretreatment means, in which the substrate 1 is immersed in a pretreatment liquid 11a such as a cleaning liquid or a surface treatment liquid, the micro-pattern 2 is immersed in the pretreatment liquid 11a, and then it is brought into contact with the organic fatty acid solution 21 and the organic fatty acid solution 21 is impregnated into the micro-pattern by liquid-liquid exchange; (2) a depressurization means, in which after the substrate 1 is immersed in the organic fatty acid solution 21, the air attached to the micro-pattern 2 is removed by depressurization, and the organic fatty acid solution 21 is impregnated into the micro-pattern; (3) a two-stage treatment means, in which the aforementioned pretreatment liquid 11a or a low-viscosity organic fatty acid solution 21 is impregnated into the micro-pattern in the first means, and in the second means, it is then brought into contact with an organic fatty acid solution 21 of normal concentration or the above-mentioned depressurization means is used. The following will explain the pretreatment methods, decompression methods, and two-stage treatment methods in that order.

[0173] (Pre-processing methods)

[0174] The aforementioned (1) pretreatment method involves immersing the substrate 1 in a pretreatment liquid 11a, such as a cleaning liquid or a surface treatment liquid, and pre-immersing the micropattern 2 in the pretreatment liquid 11a. Subsequently, the substrate 1 is brought into contact with an organic fatty acid solution 21, and the organic fatty acid solution 21 is immersed in the micropattern through liquid-liquid exchange. In this way, by pre-immersing the micropattern 2 with a liquid (cleaning liquid or surface treatment liquid), liquid-liquid exchange between the liquid and the organic fatty acid solution 21 that subsequently contacts the substrate 1 in the organic fatty acid solution processing apparatus 12 can be easily performed. As a result, the organic fatty acid solution 21 can be thoroughly immersed in the micropattern 2, and oxides or impurities (including plating solution residues) present on the surface of the conductive layer 3b within the micropattern 2 can be selectively absorbed and removed by the organic fatty acid solution 21, thereby cleaning the surface of the conductive layer 3b.

[0175] The cleaning solution can be an aqueous solvent or an organic solvent, and the surface treatment solution can be an oxide removal solution, etc. In this case, in order to allow the cleaning solution or surface treatment solution to easily penetrate into the micro-pattern 2, a decompression method can also be used. By creating a decompression state inside the container, air or bubbles that have entered the micro-pattern 2 can be removed through a so-called degassing phenomenon, allowing the cleaning solution or surface treatment solution to easily penetrate into the micro-pattern 2.

[0176] (Decompression treatment methods)

[0177] The decompression treatment methods mentioned in (2) above, such as Figure 17 and Figure 21As shown, after immersing the substrate 1 in an organic fatty acid solution 21, a depressurization process is performed in a depressurization container 61 to remove (degas) the air adhering to the micro-pattern 2, thereby allowing the organic fatty acid solution 21 to penetrate into each corner of the micro-pattern 2. Through this depressurization process, the liquid-liquid displacement between the organic fatty acid solution 21 and the nickel-containing molten solder 5 becomes easier, thus enabling the nickel-containing molten solder 5 to penetrate into each corner of the micro-pattern 2. As a result, a metal solder layer 3c can be formed in each corner of the micro-pattern 2 without defects or voids.

[0178] The pressure control range within the pressure-reducing container is selected from the following ranges based on the pattern shape or aspect ratio of the substrate being applied. Furthermore, unless otherwise specified, the pressure values ​​in this specification are defined using gauge pressure (G) with atmospheric pressure of 0 and absolute pressure (A) with complete vacuum of 0.

[0179] For through holes or trenches on the order of tens of μm, a gauge pressure range of -50 kPa to -95 kPa (absolute pressure conversion: approximately 50 kPa to 6 kPa) is preferred. This range allows for easy achievement using a general industrial vacuum pump and provides sufficient degassing force to remove larger air bubbles. A gauge pressure range of -80 kPa to -98 kPa (absolute pressure conversion: approximately 20 kPa to 3 kPa) is more preferable. Reducing the pressure to this range significantly reduces residual air within the fine pattern 2. Furthermore, for extremely fine patterns or high aspect ratio patterns, such as extremely fine slits on the order of several μm, or complex patterns with an aspect ratio exceeding 10, it is preferable to reduce the pressure to a high vacuum exceeding gauge pressure management, i.e., an absolute pressure below 100 Pa (100 Pa to 1 Pa), more preferably below 10 Pa.

[0180] Figure 17 This is a schematic diagram illustrating one example of an organic fatty acid solution processing apparatus 12. An organic fatty acid solution 21 is contained within a vacuum chamber. A substrate 1, mounted on a substrate support plate 65a connected to a mounting arm 66, is immersed and impregnated in this organic fatty acid solution 21. A cover 62 is mounted on the upper flange of the vacuum chamber 61 via a gasket 63 and a clamp 64. A vacuum pipe 67 is mounted on the cover 62, and degassing is performed to reduce the pressure inside the vacuum chamber 61. This degassing process removes air trapped or adhering to the fine patterns 2 formed on the substrate 1, allowing the organic fatty acid solution 21 to thoroughly contact or fill all corners of the fine patterns 2. Furthermore, it also allows for the removal and / or cleaning of the oxide film formed on the surface of the Cu conductive layer of the fine patterns 2.

[0181] In addition, Figure 17In this example, a total of four substrates 1 are mounted on both sides of the substrate support plate 65a. Figure 24 is an enlarged view of the configuration of the substrates 1 mounted on the substrate support plate 65a. Figure 17 The configuration of the organic fatty acid solution treatment device 12 shown is only one example and is not limited to any particular type. Figure 17 The structure shown can also take various forms. This substrate support plate 65a, used to hold and transport the substrate 1, is particularly suitable for transporting quartz or glass substrates. This substrate support plate 65a can safely transport quartz or glass substrates with excellent dimensional stability, preferably capable of forming fine patterns 2. The substrate support plate 65a preferably has a structure that fixes one or two substrates 1 with their substrate surfaces exposed, and can directly spray a stream 5a of nickel-containing molten solder 5 towards the substrate surface of the fixed substrate 1 through a spray nozzle or the like.

[0182] Figure 21 This is a schematic diagram illustrating another example of an apparatus 12 containing an organic fatty acid solution treatment device. Figure 21 In the case of substrate support member 65, for example, Figure 25 The illustrated substrate support frame 65b has multiple substrates 1 mounted on it, but it can also be... Figure 17 Or, as shown in Figure 22, a single substrate support plate 65a. This organic fatty acid solution treatment apparatus 12 uses a single-tank type depressurization vessel 61 for depressurization treatment. First, as... Figure 21 As shown in (A), one or more substrates 1 mounted on the conveyor arm 68 are moved vertically downwards (in the direction of the arrow in the figure) into a depressurized container 61 filled with an organic fatty acid solution 21, and immersed in the organic fatty acid solution 21. Then, as... Figure 21 As shown in (B), the opening at the top of the depressurization container 61 is sealed by the cover 62, gasket 63, and clamp 64, thus sealing the interior of the depressurization container 61. In this state, air is discharged from the depressurization pipe 67 provided on the cover 62, reducing the internal pressure to a predetermined vacuum level. Through this depressurization process, air trapped or attached to the micro-grooves 2a, non-through holes 2b, and through holes 2c formed on the substrate 1 is forcibly removed and discharged, allowing the organic fatty acid solution 21 to replace the removed air and reliably penetrate into every corner of the micro-pattern 2, facilitating the replacement and filling of the molten solder 5 described later. Subsequently, the pressure inside the depressurization container is restored to atmospheric pressure.

[0183] (Two-stage processing approach)

[0184] The aforementioned two-stage processing (3), as shown in Figure 22, employs two processing methods. In the first method, the aforementioned pretreatment liquid 11a or a low-viscosity organic fatty acid solution 21 is immersed in the micro-pattern 2. In the second method, it is subsequently contacted with a normal concentration organic fatty acid solution 21 or subjected to the aforementioned decompression treatment. According to this two-stage processing method, in the first method, the pretreatment liquid 11a or a low-viscosity organic fatty acid solution 21 can be immersed in the micro-pattern 2. In the second method, the liquid immersed in the micro-pattern can undergo liquid-liquid exchange with a normal concentration organic fatty acid solution 21, and the organic fatty acid solution 21 can be immersed in every corner of the micro-pattern. As a result, the organic fatty acid solution 21 can be thoroughly immersed in the micro-pattern 2, facilitating subsequent liquid-liquid exchange with the molten solder 5. Furthermore, the organic fatty acid solution 21 can selectively absorb and remove oxides or impurities (including plating solution residues) present on the surface of the conductive layer 3b within the micro-pattern 2, thereby cleaning the surface of the conductive layer 3b. Furthermore, in the first container, a low-viscosity solution of 5% by mass or more but less than 10% by mass, with a concentration approximately half that of a commonly used organic fatty acid solution 21, is preferred, thereby improving the penetration efficiency to all corners of the micro-pattern. While less than 5% is less effective for cleaning purposes, it is only suitable for ensuring penetration (low viscosity) in the first method. In the subsequent second container, treatment with an organic fatty acid solution 21 at a higher concentration (e.g., 10% by mass or more but less than 25%) allows for easy liquid-liquid exchange within the micro-pattern 2.

[0185] Figure 22(A) is an example of the first method, and Figure 22(B) is an example of the second method. Either the first method or the second method can be equipped with a pressure-reducing treatment means having a pressure-reducing container 61 and pressure-reducing piping 67, etc. The first method in Figure 22(A) uses a pretreatment liquid device 11, and the second method in Figure 22(B) uses a treatment device 12 containing an organic fatty acid solution, but is not limited to this configuration.

[0186] When both the first and second methods are configured as an organic fatty acid solution processing apparatus 12, the two containers shown in FIG22 can be configured as a first container and a second container having organic fatty acid solutions of different viscosities, respectively. In this case, the first container has an organic fatty acid solution 21 with a lower viscosity than the second container, and the second container preferably has an organic fatty acid solution with the same concentration as the organic fatty acid solution used to refine the molten solder 5 subsequently used in the metal solder layer forming apparatus 13. With the first container having a low-viscosity organic fatty acid solution, the organic fatty acid solution is easily immersed into the micro-pattern. Subsequently, with the second container, the organic fatty acid solution 21 with the same concentration as the organic fatty acid solution used to refine the molten solder 5 can easily immerse the micro-pattern 2 into which the low-viscosity organic fatty acid solution has already been immersed. As a result, the molten solder 5 can be easily immersed into the micro-pattern 2, and the metal solder layer 3c can be filled to every corner of the micro-pattern 2 without defects or gaps.

[0187] The first container can also be equipped with a decompression treatment method to remove air from the micro-pattern 2, allowing the low-viscosity organic fatty acid solution to penetrate into every corner of the micro-pattern 2. In this way, the subsequent penetration of the organic fatty acid solution 21 in the second container becomes easier, and through liquid-liquid displacement between the organic fatty acid solution 21 and the nickel-containing molten solder 5, the nickel-containing molten solder 5 can be penetrated into every corner of the micro-pattern 2. As a result, a metal solder layer 3c can be formed in every corner of the micro-pattern 2 without defects or voids.

[0188] Furthermore, the concentration A (mass%) of the organic fatty acid solution in contact with the micro-pattern 2 and the concentration B (mass%) of the organic fatty acid solution used to refine the nickel-containing molten solder 5 are preferably A = B, or A < B. By setting the concentration A of the organic fatty acid solution in contact with the micro-pattern 2 as described above, liquid-liquid displacement between the organic fatty acid solution 21 immersed in the micro-pattern and the nickel-containing molten solder 5 becomes easier.

[0189] (Metal solder layer formation apparatus / process)

[0190] The metal solder layer forming apparatus 13 / process is an apparatus / process that supplies a flow 5a of nickel-containing molten solder 5 treated with an organic fatty acid solution to a substrate 1 in contact with an organic fatty acid solution 21, so as to fill the fine pattern 2 with a metal solder layer 3c. Specifically, the apparatus / process supplies a flow 5a of nickel-containing molten solder 5 treated with an organic fatty acid solution 21 to the conductive layer 3b on the inner surface of the fine pattern 2, so as to fill the fine pattern 2 with a metal solder layer 3c. The part about forming the metal solder layer 3c with the molten solder 5 has already been described in detail, so its description is omitted here.

[0191] More specifically, this metal solder layer forming apparatus 13 / process, such as Figure 13 As shown in Figure 18, the apparatus / process includes supplying a liquid stream 5a containing nickel-containing molten solder 5 to allow the molten solder 5 to adhere, followed by... Figure 14 and Figure 19 As shown, a device / process for removing excess molten solder 5b may also be included as needed. This molten solder 5 solidifies within the micro-pattern 2, thereby forming a metallic solder layer 3c.

[0192] In the molten solder attachment apparatus / process shown in Figure 18, a substrate 1, in which an organic fatty acid solution 21 is immersed in each corner of the micropattern 2, is sprayed with a stream 5a of nickel-containing molten solder refined by the organic fatty acid solution from molten solder spray nozzles 31 disposed on both sides of the substrate support plate 65a. At this time, although the molten solder spray nozzles 31 are arranged in a direction orthogonal to the substrate 1 (right angle direction) in Figure 18, there is no particular limitation. For example, the molten solder spray nozzles 31 can be arranged to spray from slightly below upwards towards the substrate 1 at an angle, or from slightly above downwards towards the substrate 1 at an angle, or in one to three positions selected from the orthogonal position, the angled downwards position, and the angled upwards position. Thus, the organic fatty acid solution 21 immersed in each corner of the micropattern 2 is replaced with molten solder 5, and the molten solder 5 adheres to and fills the surface of the conductive layer 3b composed of a copper layer or a copper alloy layer. Furthermore, at this time, if... Figure 11 As explained in the description, when the molten solder 5 contacts the conductive layer 3b located on the surface of the fine pattern 2, a CuSn intermetallic compound layer 7 and a CuNiSn intermetallic compound layer 4 (copper corrosion prevention layer) are generated on the surface of the conductive layer 3b. Therefore, it can prevent the conductive layer 3b from being damaged or disappearing due to the corrosion of copper contained in the conductive layer 3b.

[0193] Additionally, if the remaining molten solder 5b is removed, as follows: Figures 14 to 16 As shown, the spraying is preferably performed by spraying a liquid stream 32a containing an organic fatty acid solution, or a gas stream of air or inert gas. Spraying is preferably performed from a solution spray nozzle 32, and the spraying angle θ of the liquid stream 32a or the gas stream is preferably adjusted arbitrarily.

[0194] Figure 19This also shows an example of the residual solder removal apparatus 14 / process. In this residual solder removal apparatus 14 / process, a heated organic fatty acid solution is sprayed as a jet stream 32a from solution jet nozzles 32 disposed on both sides of the substrate 1. Although the jet stream 32a sprayed from the solution jet nozzles 32 can be sprayed from any direction relative to the substrate 1, since this jet stream 32a is used to remove residual solder, therefore... Figure 19 As shown, it is preferable to scrape the remaining solder downwards by spraying from an obliquely upward direction toward the substrate 1. Therefore, the solution spray nozzle 32 is preferably configured to face obliquely downwards relative to the substrate 1, and is preferably controlled to supply solution with a narrow spray width. With this acute-angle spray, the remaining molten solder that only protrudes above the surface of the substrate can be effectively scraped off, leaving only the desired solder inside the pattern.

[0195] Furthermore, in the aforementioned metal solder layer forming apparatus / process, for example, Figure 15 and Figure 16 As shown, it is preferable to set the space 42 in a vapor atmosphere containing an organic fatty acid solution 41, and to form the metal solder layer 3c in this vapor atmosphere. Furthermore, in the metal solder layer forming apparatus / process, as described above, it is preferable to spray the molten solder 5 toward the direction of the fine pattern 2 or at a predetermined angle. Figure 13 , Figure 15 and Figure 16 For example, a flow of molten solder is sprayed from the spray nozzle 31 toward the fine pattern 2 (in a way that it comes into contact with the substrate surface at a right angle).

[0196] (Drainage device / process for organic fatty acid solution)

[0197] After spraying a stream of organic fatty acid solution to remove the remaining molten solder 5b, an air knife (not shown) can be used as needed to remove the organic fatty acid solution. An air knife, such as... Figure 16 As shown, the solution is preferably applied to the surface of a substrate 53 that has been pulled up from the organic fatty acid solution 41 and from which residual molten solder has been removed, to remove the organic fatty acid solution 41. The gas injected from the air knife can be clean air, or an inert gas such as nitrogen or argon. This dehydration removes excess attached organic fatty acid solution 41. This dehydration is preferably performed using an air nozzle or the like. The injection pressure of the air nozzle or the like is not particularly limited and can be set arbitrarily.

[0198] Figure 20 This also shows an example of the liquid removal device 15 / process. After the process of removing residual solder, high-pressure air (air jet 33a) is injected from an air jet nozzle 33 facing downwards. (The text abruptly ends here.) Figure 19The process for removing residual solder is the same as shown, in which air is supplied to the substrate surface with a narrow spray width, thereby obtaining a treated substrate after the organic fatty acid solution adhering to the substrate surface has been removed.

[0199] (Overall structure of the manufacturing equipment)

[0200] Figure 23 This is an explanatory diagram showing an example of each device constituting the micro-solder pattern forming substrate manufacturing apparatus 20 of the present invention. The manufacturing apparatus 20 of the present invention arranges the organic fatty acid solution treatment apparatus 12, the metal solder layer forming apparatus 13, the residual solder removal apparatus 14, and the liquid removal apparatus 15, which have been described in detail, in sequence, and transports the substrate 1 by the transport means 16 in this order for processing. In particular, by using the organic fatty acid solution treatment apparatus 12, the micro-pattern 2 is immersed in the organic fatty acid solution 21, and then the immersed organic fatty acid solution 21 is subjected to liquid-liquid displacement with the nickel-containing molten solder 5, thereby allowing the metal solder layer 3c to fill every corner of the micro-pattern 2 without gaps. This technique enables gapless, high-density mounting and high reliability.

[0201] Furthermore, the details already described in the "Structure of the Micro-solder Pattern Forming Substrate 10" section are omitted here in the manufacturing method description section to avoid repetition.

[0202] [The shape of the fine pattern]

[0203] Figure 26 and Figure 27 A representative form of a micropattern 2 formed on the main surface of substrate 1 (mainly the substrate surface on the side where micro-wires or micro-solder bumps are formed) is shown. These micropatterns 2 can be formed individually on the same substrate by a specific pattern, or multiple micropatterns can be formed. In addition, various micropatterns 2 (grooves, non-through holes, through holes, etc.) can also be formed in combination on the same substrate.

[0204] Figure 26 (A) is an example of a trench 2a suitable for forming wiring, etc. The trench 2a is formed on the surface of the substrate 1 and is a linear recess with a predetermined width and depth. This trench 2a is filled with a conductive material (metal solder) to form fine wiring, etc. By applying the present invention to a substrate 1 with such trench 2a, since the organic fatty acid solution 21 and the molten solder 5 can reach the fine parts of the trench 2a, the metal solder layer 3c can be filled seamlessly to each corner of the elongated trench 2a. As a result, fine wiring, etc., can be formed on the substrate surface.

[0205] Figure 26(B) is an example of a non-through-hole 2b applied to the formation of solder bumps, etc. The non-through-hole 2b is formed independently on the surface of the substrate 1 and has a recess (non-through-hole) of predetermined size and depth. This non-through-hole 2b is filled with a conductive material (metal solder) to form fine solder bumps, etc. By applying the present invention to a substrate 1 having such non-through-hole 2b, since the organic fatty acid solution 21 and molten solder 5 can reach the fine parts of the non-through-hole 2b, the metal solder layer 3c can be filled seamlessly to every corner of the tiny non-through-hole 2b. As a result, fine solder bumps, etc., serving as mounting terminals for electronic components, can be formed on the substrate surface. Alternatively, a land can be formed for forming fine solder bumps, etc., serving as connections between multilayer substrates.

[0206] Figure 27 (A) is an example in which a trench 2a forming a wiring harness or the like is combined with a non-through hole 2b forming a solder bump or the like. The trench 2a and the non-through hole 2b are as described above. Figure 26 (A) and Figure 26 (B) As explained. The trench 2a and the non-through hole 2b are connected and formed. By applying the present invention to a substrate 1 having such trenches 2a and non-through holes 2b, since the organic fatty acid solution 21 and the molten solder 5 can reach the details of the trenches 2a and non-through holes 2b, the metal solder layer 3c can be filled into every corner of the fine trenches 2a and the tiny non-through holes 2b without gaps. As a result, fine wiring and fine solder bumps can be formed on the substrate surface. In this configuration, since the wiring portion and the solder bump portion can be integrally formed in the same filling process, the reliability of the electrical connection is greatly improved.

[0207] Figure 27 (B) is an example of combining a trench 2a for forming wiring, a non-through hole 2b for forming solder bumps, and a narrow-diameter through hole 2c for forming through holes. The trench 2a and the non-through hole 2b are combined as described above. Figure 26 (A) and Figure 26 (B) As described. The narrow-diameter through-hole 2c (also called a through-hole) is a through-hole that penetrates both sides of the substrate 1, used for electrically connecting the surface and back sides. Figure 27In (B), the through-hole 2c, trench 2a, and non-through-hole 2b are interconnected. By applying the present invention to a substrate 1 having such trench 2a, non-through-hole 2b, and through-hole 2c, since the organic fatty acid solution 21 and molten solder 5 can reach the details of the trench 2a, non-through-hole 2b, and through-hole 2c, the metal solder layer 3c can be filled seamlessly into every corner of the fine trench 2a, the tiny non-through-hole 2b, and the narrow-diameter through-hole 2c. In this configuration, electrical paths can be continuously connected from the wiring and bumps on the substrate surface to the interior (or back side) of the substrate. In particular, by applying the decompression treatment method of the present invention, even the interior of the through-hole 2c, which is complexly interconnected in this manner and has a high aspect ratio, can be reliably filled with the organic fatty acid solution 21 and molten solder 5 without leaving any air bubbles. As a result, fine wiring or fine solder bumps can be formed on the substrate surface, thereby enabling electrical connection between the surface and back of the substrate 1. In this configuration, since the wiring portion and solder bump portion can be integrally formed in the same filling process, the reliability of the electrical connection is greatly improved.

[0208] The characteristic technique of this invention, namely the decompression treatment method, is extremely effective in removing residual air from internal spaces that are thus complexly branched and interconnected.

[0209] Other examples of manufacturing apparatus

[0210] Figure 30 and Figure 31 An example of a vertical, cassette-feed type manufacturing apparatus 400 is shown. This manufacturing apparatus 400 is used to illustrate a preferred embodiment of the present invention and does not limit the technical scope of the present invention. Furthermore, this manufacturing apparatus 400 is an apparatus obtained by applying the apparatus configuration described in Patent Document 6 (Japanese Patent No. 6150881) to the present invention.

[0211] Figure 30 and Figure 31The welding apparatus 400 shown includes: a first processing tank (inlet tank) 401, on which a processing substrate 500 is disposed; a second processing tank (pre-processing apparatus) 402, which pre-processes the processing substrate 500 fed from the first processing tank 401; a third processing tank (organic fatty acid solution processing apparatus) 403, which contacts the processing substrate fed from the second processing tank 402 with an organic fatty acid solution; and a fourth processing tank (metal solder layer forming apparatus) 404, which has a molten solder layer forming apparatus for adhering molten solder 5 to the processing substrate processed in the third processing tank 403. The means for attaching molten solder and the means for removing molten solder from the aforementioned attached molten solder 5; a fifth processing tank (liquid removal device) 405, which processes the micro-solder pattern forming substrate processed in the fourth processing tank 404 with gas or liquid; a sixth processing tank (connecting tank) 406, which sends the micro-solder pattern forming substrate fed from the fifth processing tank 405 to the next seventh processing tank 407; and a seventh processing tank (exit tank) 407, which takes out the micro-solder pattern forming substrate 600 fed from the sixth processing tank 406.

[0212] The following is a detailed explanation.

[0213] Figure 30 and Figure 31 The welding apparatus 400 shown comprises a first processing tank 401, a second processing tank 402, a third processing tank 403, a fourth processing tank 404, a fifth processing tank 405, a sixth processing tank 406, and a seventh processing tank. The five processing tanks, from the second to the sixth processing tank 406, are arranged within a processing chamber 431. They are arranged radially from the inside out, with the arm rotation axis 432 as the center, so that the elongated processing tanks are evenly spaced (e.g., at 72° intervals). Alternatively, this spacing may not be equal.

[0214] Although the first processing tank 401 and the seventh processing tank 407 are located outside the processing box 431, as Figure 31 As shown, the first processing tank 401 and the second processing tank 402 are connected at the bottom, and the seventh processing tank 407 is connected at the bottom to the sixth processing tank 406. Each of the processing tanks 401, 402, 406, and 407 ensures a longitudinal space sufficient for the processing substrates 500 and 600 to pass through, in which the processing substrate 500 and the micro solder pattern forming substrate 600 slide and move.

[0215] Next to the first processing tank 401, an inlet stacker 411 for storing the processing substrate 500 is disposed. The processing substrate 500 is stored in this inlet stacker 411. On the other hand, next to the seventh processing tank 407, an outlet stacker 421 for storing the processed micro solder pattern forming substrate 600 is disposed. The processed micro solder pattern forming substrate 600 is stored in this outlet stacker 421.

[0216] These processing slots are configured in a cover that covers the entire structure. The inlet stacker 411 and the outlet stacker 421 are configured such that a portion of them extends outside the cover 433 so that the processing substrate 500 can be moved in and out from outside the cover 433.

[0217] The first processing tank 401 is fed into the inlet stacker 411. This feeding is performed by a robotic arm 436, which clamps the processing substrate 500 using a clamping member 437 located at the front end of the robotic arm 436. This first processing tank 401 contains, for example, a pretreatment liquid or a low-viscosity organic fatty acid solution. Since the first processing tank 401 is connected to the second processing tank 402, the second processing tank 402 also contains a pretreatment liquid or an organic fatty acid solution. In addition, the first processing tank 401 has a structure in which the cover closes immediately after the arm is raised, and the seventh processing tank 407 also has the same structure in which the cover closes immediately after the arm is raised.

[0218] The processing substrate 500, which enters the first processing tank 401, moves from the first processing tank 401 to the second processing tank 402 via the sliding member 438. This movement method is not particularly limited, but for example... Figure 31 As shown, this movement can be achieved by a sliding frame 501 reciprocating within the first processing tank 401 and the second processing tank 402. The sliding frame 501 can be moved by a sliding member 438, the drive for which is transmitted from the clamping member 437 to the sliding member 438. For example, by rotating the clamping member 437, the sliding member 438 functions to reciprocate the sliding frame 501. Furthermore, this movement between the sixth processing tank 406 and the seventh processing tank 407 can also be performed using the same principle. Additionally, symbol 412 represents an input device, symbol 413 represents an arm extending from the input device, symbol 422 represents a discharge device, and symbol 423 represents an arm extending from the input device.

[0219] The processing substrate, moved to the second processing tank 402, is clamped at the front end of the suspension arm 435 located at the front end of the rotating arm 434 and pulled upwards. The pulled-up processing substrate... Figure 30 As shown, the device rotates to the position of the third processing tank 403 via the rotating arm 434, descends, and enters the third processing tank 403 while being held by the suspension arm 435.

[0220] The third processing tank 403 is a vacuum processing tank containing a heated organic fatty acid solution, in which the processing substrate undergoes vacuum processing.

[0221] The processed substrate is lifted by the suspension arm 435, such as Figure 30As shown, the device rotates to the position of the fourth processing tank 404 via the rotating arm 434, descends, and enters the fourth processing tank 404 while being held by the suspension arm 435.

[0222] The fourth processing tank 404 is used for the treatment of attaching molten solder and the removal of excess molten solder from the attached molten solder. The attachment of molten solder can be performed by immersion in the fourth processing tank 404 filled with molten solder, or by spraying the molten solder toward the substrate surface. Furthermore, excess molten solder is removed by spraying a gas such as nitrogen or air, or a solution containing organic fatty acids, toward the substrate surface to remove any remaining solder adhering to the processed substrate surface.

[0223] The fourth processing tank 404 may be equipped with a molten solder circulation tank 441, a filter 442, and a gear pump 443. The molten solder circulation tank 441 is preferably used to circulate the molten solder, whether in immersion or spraying conditions. The filter 442 is used to separate impurities or organic fatty acid solutions mixed into the molten solder; a cyclone filter is preferred.

[0224] The processed substrate is lifted by the suspension arm 435, and as... Figure 30 As shown, the device rotates to the position of the fifth processing tank 405 via the rotating arm 434, descends, and enters the fifth processing tank 405 while being held by the suspension arm 435.

[0225] The fifth processing tank 405 is used to process the processed substrate with gas or liquid. Specifically, it removes organic fatty acid solutions and the like adhering to the substrate surface. Examples of such methods include air spraying and inert gas spraying. Alternatively, it can be filled with any cleaning solution and processed with that cleaning solution.

[0226] The processed substrate is lifted by the suspension arm 435, and as... Figure 30 As shown, the device rotates to the position of the sixth processing tank 406 via the rotating arm 434, descends, and enters the sixth processing tank 406 while being held by the suspension arm 435.

[0227] The sixth processing tank 406 contains a solvent used to isolate the atmosphere inside the processing chamber from the external atmosphere. The solvent can be the aforementioned organic fatty acid solution, or other organic solutions such as alcohol. Similarly, the organic fatty acid solutions filling the first processing tank 401 and the second processing tank 402 also contain a solvent used to isolate the atmosphere inside the processing chamber from the lower atmosphere. Isolating the atmosphere inside and outside the processing chamber using this solution is a crucial technical element in fusion welding apparatuses. This isolation prevents the high-temperature atmosphere and the organic fatty acid solution atmosphere inside the processing chamber from diffusing to the outside.

[0228] As explained above, based on Figure 30 and Figure 31 The welding apparatus 400 and the welding method using it, as shown, allow for short processing times in each processing tank, enabling sequential processing while the arm rotates. This results in significant space-saving and miniaturization of the apparatus, making it a low-cost and highly efficient welding device. Furthermore, by effectively isolating the atmosphere inside and outside the processing tank, the leakage of oily odors from organic fatty acid solutions can be prevented. Based on this apparatus and method, it is possible to manufacture substrates or electronic components with high reliability and yield as electrodes for electrical connections at low cost.

[0229] in addition, Figure 30 and Figure 31 The radial slot arrangement centered on the arm rotation axis 432 shown helps to optimize the installation space, but it is not limited to this. For example, it can also be a series-type (in-line) arrangement of the processing slots in a straight line, or a grid-like arrangement in which multiple robotic arms transport substrates in parallel. Furthermore, regarding the holding and movement of the sliding frame 501, which serves as a substrate support plate, not only the rotating arm 434 shown can be used, but also a crane-type crane, a vertical multi-joint robot, or a chain-driven vertical circulating conveyor belt, etc., to automate or semi-automate the entire process.

[0230] also, Figure 30 The cover function of the third processing tank 403, etc., which performs depressurization treatment, can be a sliding shutter structure, or a configuration that houses the container itself within the vacuum chamber, in addition to the sealing provided by a cover plate that rises and falls in conjunction with the movement of the arm. Furthermore, a sensor monitoring the state of the air exhausted from the depressurization piping can be installed, and feedback control can be implemented to instantly determine whether degassing within the fine pattern is complete based on the amount of exhaust air or the rate at which the vacuum level is reached. The depressurization treatment device can have individual vacuum pumps installed in each container, or it can be configured to supply depressurized air from a centralized vacuum line at the factory via valve control.

[0231] exist Figure 30 In the metal solder layer forming apparatus shown (such as the fourth processing tank 404), the moving speed of the sliding frame 501, which serves as a substrate support plate, and the solder spraying pressure can be optimized and controlled for each substrate's ID (identification information). For example, for substrates with micro-grooves having extremely high aspect ratios, the conveying speed of the sliding frame 501 can be reduced, and the spraying nozzle 31 can be oscillated relative to the substrate surface, or a pulsed liquid flow can be sprayed, thereby physically promoting liquid-liquid displacement between the organic fatty acid solution and the molten solder. Furthermore, the number of spraying nozzles is not particularly limited, and multiple nozzles or automatic nozzle position adjustment mechanisms can be added depending on the size or pattern distribution of the substrate.

[0232] Figure 30 The circulating purification system, including the solder circulation tank 441, filter 442, and gear pump 443, can be installed externally or integrated with the processing tank 431. In particular, a purification unit can be provided to forcibly degas and dry water or volatile components mixed into the organic fatty acid solution during processing in the vacuum treatment vessel, thereby maintaining the solution's oxidation prevention capability at its highest level.

[0233] In addition to the overall sealing of the device by the cover 433, air curtains or nitrogen curtains can be formed at the openings of each processing tank to more tightly prevent the intrusion of external air or the leakage of vapors containing organic fatty acid solutions. Furthermore, the system may include a drain pan located below the transport path to collect the solution dripping from the sliding frame 501, which serves as a substrate support plate, as it moves between tanks, and to automatically purify and reuse the collected liquid.

[0234] Example

[0235] The present invention will be described in more detail by way of examples.

[0236] [Example 1]

[0237] As an example, a micropatterning substrate 1 was prepared by forming a micropattern 2 with multiple through holes 2c of 40 μm diameter at a spacing of 150 μm on a quartz substrate with a diameter of 4 inches and a thickness of 0.22 mm. In this micropattern 2, as... Figure 8 As shown in (A), a first conductive layer 3a with a thickness of 0.25 μm is formed on both sides (1a, 1b) of the substrate and the inner surface of the fine pattern 2 by sputtering. Subsequently, as... Figure 8 As shown in (B), the second conductive layer 3b is formed on the first conductive layer 3a by a chemical plating method using a chemical copper plating solution, resulting in a second conductive layer 3b with a thickness of 5 μm composed of a copper plating layer. Subsequently, as... Figure 8 As shown in (C), the first conductive layer 3a and the second conductive layer 3b formed on the substrate surfaces 1a and 1b are removed by mechanical polishing. Subsequently, as... Figure 8 As shown in (D), the organic fatty acid solution 21 is immersed into the fine pattern. Subsequently, as... Figure 8 (E) and Figure 13 As shown, molten solder 5, treated with an organic fatty acid solution 21, is sprayed to fill the micro-pattern 2 with a metal solder layer 3c. Subsequently, it is processed as follows... Figure 14 The method shown removes the remaining molten solder 5b. Thus, a product is manufactured. Figure 1 and Figure 3 The micro solder pattern shown forms the substrate 10.

[0238] The molten solder 5 used is a pentagonal lead-free solder composed of Ni: 0.05% by mass, Ge: 0.005% by mass, Ag: 3% by mass, Cu: 0.5% by mass, with the balance being Sn, and is heated to 250°C to prepare it as molten solder 5. The solder structure of the filled metal solder layer 3c becomes... Figure 6 The tissue exhibits the same microgranular crystalline structure as shown. Furthermore, it forms as... Figure 11 (A) shows the copper corrosion prevention layer 4, which inhibits the excessive formation of the CuSn intermetallic compound layer 7. The resulting fine solder pattern forms the substrate 10, with no residual plating solution or chemical components in the vias, and no defects or voids are generated in the via conductors.

[0239] [Example 2]

[0240] As another example, a micropatterning substrate 1 was prepared by forming a plurality of through holes 2c with a diameter of 20 μm at a spacing of 150 μm on a quartz substrate with a diameter of 4 inches and a thickness of 0.26 mm. Otherwise, the same as in Example 1, a micropatterning substrate was fabricated. Figure 2 The micro-solder pattern forming substrate 10 of Embodiment 2 is shown. In this micro-solder pattern forming substrate 10, the solder structure of the filled metal solder layer 3c also becomes similar to... Figure 6 The microgranular crystalline structure shown is identical to the one described. Furthermore, Example 2 also similarly formed a microgranular crystalline structure. Figure 11 (A) shows the copper corrosion prevention layer 4, which suppresses the excessive formation of the CuSn intermetallic compound layer 7. In addition, the resulting fine solder pattern forming substrate 10 has no residual plating solution or chemical components in the through holes, and no defects or voids are generated in the through hole conductors.

[0241] [Example 3]

[0242] As another example, fine patterns with a diameter of 150 μm were formed at a spacing of 300 μm on an alkali-free glass substrate with a diameter of 12 inches and a thickness of 0.30 mm, thus preparing a pattern as shown below. Figure 4 The substrate 1 is formed by a fine pattern with 700,000 holes. The first conductive layer 3a is as follows: Figure 5 As shown, the thickness is set to 0.8 μm (8000 angstroms). Otherwise, the same as in Example 1, the micro-solder pattern forming substrate 10 of Example 3 was fabricated. In this micro-solder pattern forming substrate 10, the solder structure of the filled metal solder layer 3c also becomes similar to... Figure 6 The microgranular crystalline structure shown is identical to the tissue morphology. Furthermore, Example 3 also similarly formed a microgranular crystalline structure. Figure 11 (A) shows the copper corrosion prevention layer 4, which suppresses the excessive formation of the CuSn intermetallic compound layer 7. In addition, the resulting fine solder pattern forming substrate 10 has no residual plating solution or chemical components in the through holes, and no defects or voids are generated in the through hole conductors.

[0243] [Example 4]

[0244] Microgrooves 2a, 30 μm wide and 200 μm deep, were formed on a quartz substrate with a thickness of 0.5 mm. Figure 17 In the single-layer pressure-reducing vessel shown, after the pressure inside the vessel was reduced to -90 kPa (gauge pressure) and the air was removed, nickel-containing molten solder 5 was supplied. The results confirmed that the metal solder layer 3c filled the bottom of the trench 2a without any voids.

[0245] [Example 5]

[0246] Microgrooves 2a with an aspect ratio of 20 (5 μm width, 100 μm depth) were formed on a quartz substrate with a thickness of 0.5 mm. Figure 17 In the single-layer depressurization vessel shown, after the pressure inside the vessel is reduced to an absolute pressure of 10 Pa for high-vacuum exhaust, nickel-containing molten solder 5 is supplied. As a result, even in an extremely narrow space where capillary phenomena and surface tension have a significant impact, complete metallizing without any gaps until the bottom is achieved.

[0247] Explanation of reference numerals in the attached figures

[0248] 1:Substrate

[0249] 1a: Top surface of substrate

[0250] 1b: Bottom surface of substrate

[0251] 2: Micro-patterns

[0252] 2a: Trench

[0253] 2b: Non-through hole

[0254] 2c: Through hole

[0255] 3: Metal layer

[0256] 3a: First conductive layer

[0257] 3b: Conductive layer (second conductive layer)

[0258] 3c: Metal solder layer

[0259] 4: Copper corrosion prevention layer (intermetallic compound layer)

[0260] 5: Molten solder

[0261] 5a: Flow of molten solder

[0262] 5b: Remaining molten solder

[0263] 7: CuSn intermetallic compound layer

[0264] 10: Micro-solder pattern forming substrate

[0265] 11: Pre-treatment device

[0266] 11a: Pretreatment solution

[0267] 12: Organic fatty acid solution treatment device

[0268] 13: Metal solder layer forming apparatus

[0269] 14: Residual solder removal device

[0270] 15: Liquid removal device

[0271] 16: Transportation methods

[0272] 20: Manufacturing equipment

[0273] 21: Solution containing organic fatty acids

[0274] 22: Anti-corrosion film

[0275] 23: Chemical plating catalyst

[0276] 31: Filling method (molten solder spray nozzle)

[0277] 32: Injection method (injection nozzle containing organic fatty acid solution)

[0278] 32a: Jet stream (containing organic fatty acid solution)

[0279] 33: Injection method (injection nozzle for liquid air)

[0280] 33a: Jet air

[0281] 41: Solution containing organic fatty acids

[0282] 42: Space Department

[0283] 51: Substrate treated with organic fatty acid solution

[0284] 52: Substrate after molten solder filling

[0285] 53: Substrate after removing remaining molten solder

[0286] 61: Pressure Relief Container

[0287] 62: Cover

[0288] 63: Padding

[0289] 64: Fixture components

[0290] 65: Substrate support component

[0291] 65a: Substrate support plate

[0292] 65b: Substrate support frame

[0293] 66: Mounting arm

[0294] 67: Pressure reducing piping

[0295] 400: Welding equipment

[0296] 401: First processing tank

[0297] 402: Second processing tank

[0298] 403: Third processing tank

[0299] 404: Fourth processing tank

[0300] 405: Fifth processing tank

[0301] 406: Sixth Processing Tank

[0302] 407: Seventh Processing Tank

[0303] 411: Inlet Stacker

[0304] 412: Input device

[0305] 413: Arm

[0306] 421: Export Stacker

[0307] 422: Discharge device

[0308] 423: Arm

[0309] 431: Processing box

[0310] 432: Arm Rotation Axis

[0311] 433: Cover

[0312] 434: Rotating Arm

[0313] 435: Suspension arm

[0314] 436: Robotic Arm

[0315] 437: Clamping component

[0316] 438: Sliding component

[0317] 441: Molten Solder Circulation Box

[0318] 442: Filter

[0319] 443: Gear Pump

[0320] 500, 510, 520, 530, 540: Processing substrate

[0321] 501: Sliding bracket

[0322] 600: Micro solder pattern forming substrate

Claims

1. An apparatus for manufacturing a substrate with a fine solder pattern, wherein the fine solder pattern formed on the substrate is filled with a metal solder layer, characterized in that, have: An apparatus for processing an organic fatty acid solution, wherein the organic fatty acid solution is brought into contact with a substrate, the substrate having a conductive layer of copper or a copper alloy formed on the inner surface of the fine pattern; and A metal solder layer forming apparatus supplies a flow of nickel-containing molten solder treated with an organic fatty acid solution to the substrate in contact with the substrate, so as to fill the fine pattern with a metal solder layer.

2. The manufacturing apparatus for forming a substrate with fine solder patterns according to claim 1, wherein, The organic fatty acid solution processing device has a depressurization process, which degasses the air adhering to the micro-pattern and allows the organic fatty acid solution to penetrate into every corner of the micro-pattern.

3. The manufacturing apparatus for forming a substrate with fine solder patterns according to claim 1, wherein, The organic fatty acid solution processing device has a first container and a second container, which respectively contain organic fatty acid solutions with different viscosities. The viscosity of the organic fatty acid solution contained in the first container is lower than that of the organic fatty acid solution contained in the second container. The concentration of the organic fatty acid solution contained in the second container is the same as the concentration of the organic fatty acid solution used in the refining of the molten solder in the metal solder layer forming device.

4. The manufacturing apparatus for forming a substrate with fine solder patterns according to claim 3, wherein, The first container is equipped with a depressurization process, which degasses the air adhering to the micro-pattern and allows the low-viscosity organic fatty acid solution to penetrate into every corner of the micro-pattern.

5. The manufacturing apparatus for forming a substrate with fine solder patterns according to claim 1 or 2, wherein, The device includes a supplying apparatus that supplies the substrate, on which a conductive layer of copper or a copper alloy is formed on the inner surface of the fine pattern, to the organic fatty acid solution processing apparatus.

6. The manufacturing apparatus for forming a substrate with fine solder patterns according to claim 1 or 2, wherein, It is equipped with a conductive layer forming apparatus, which forms a conductive layer made of copper or a copper alloy on the inner surface of the fine pattern.

7. The manufacturing apparatus for forming a substrate with fine solder patterns according to claim 1 or 2, wherein, The micro-pattern is a single type of pattern selected from through holes, non-through holes, grooves and slits, or a composite pattern of two or more types.

8. The manufacturing apparatus for forming a substrate with fine solder patterns according to claim 1 or 2, wherein, The concentration A (mass%) of the organic fatty acid solution in contact with the micropattern and the concentration B (mass%) of the organic fatty acid solution used to process the nickel-containing molten solder are A=B or A <B。 9. The manufacturing apparatus for forming a substrate with fine solder patterns according to claim 1 or 2, wherein, The substrate is a quartz substrate or a glass substrate, and has a substrate support plate for holding and transporting the substrate.

10. A method for manufacturing a substrate with a fine solder pattern, characterized in that the fine solder pattern formed on the substrate is filled with a metal solder layer to form the substrate, wherein the fine solder pattern is formed on the substrate and the substrate is filled with a metal solder layer. have: An organic fatty acid solution processing step is included, in which the organic fatty acid solution is brought into contact with the substrate, wherein a conductive layer made of copper or a copper alloy is formed on the inner surface of the fine pattern on the substrate; and The metal solder layer formation process involves supplying a stream of nickel-containing molten solder treated with the organic fatty acid solution to the substrate that has come into contact with the substrate, so as to fill the fine pattern with the metal solder layer.

11. The method for manufacturing a substrate with a fine solder pattern according to claim 10, wherein, In the organic fatty acid solution treatment process, a depressurization process is performed to remove air from the micro-patterns and allow the organic fatty acid solution to immerse itself in the micro-patterns.

12. The method for manufacturing a substrate with a fine solder pattern according to claim 10, wherein, The organic fatty acid solution treatment process uses a first container and a second container. The first container and the second container respectively contain organic fatty acid solutions with different viscosities. The viscosity of the organic fatty acid solution contained in the first container is lower than that of the organic fatty acid solution contained in the second container. The concentration of the organic fatty acid solution contained in the second container is the same as the concentration of the organic fatty acid solution used in the process of refining the molten solder used to form the metal solder layer.

13. The method for manufacturing a substrate with a fine solder pattern according to claim 12, wherein, The first container is equipped with a depressurization process, which degasses the air adhering to the micro-pattern and allows the low-viscosity organic fatty acid solution to penetrate into every corner of the micro-pattern.

14. A substrate for forming a fine solder pattern, which is a substrate manufactured by the manufacturing apparatus for forming a fine solder pattern according to claim 1 or the manufacturing method for forming a fine solder pattern according to claim 10, characterized in that, The substrate has a metal layer formed on a fine pattern, which, from the inner wall surface of the fine pattern toward the stacking direction, consists of at least, in sequence, a conductive layer made of copper or a copper alloy, a mixed layer of a copper corrosion prevention layer and a copper-tin intermetallic compound layer, and a metal solder layer formed by solidification of nickel-containing molten solder.

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